COVID19

Category A agents (cholera,

plague). Patients should be placed
in separate rooms or cohorted
together. Negative pressure rooms
are not generally needed. The
rooms and surfaces and equipment
should undergo regular
decontamination preferably with
sodium hypochlorite. Healthcare
workers should be provided withfit
tested 95 respirators and protective
suits and goggles. Airborne
transmission precautions should be
taken during aerosol generating
procedures such as intubation,
suction
 and tracheostomies. A contacts
including healthcare workers
should
be monitored for development of
symptoms of COVID-19. Patients
can be discharged from isolation
once they are afebrile for atleast 3d
and have two consecutive negative
molecular tests at 1 d sampling
interval. This recommendation is
different from
pandemic flu where patients were
considerable protection in mice
against a MERS- CoV lethal
challenge. Such antibodies may
play a crucial role in enhancing
protective humoral responses
against the emerging Cos by
aiming
appropriate epitopes and functions
of the S protein. The cross-
neutralization ability of SARS-
CoV BD- specific neutralizing
MAbs considerably relies on the
resemblance between their RBDs;
therefore, SARS-CoV RBD-
specific antibodies could cross-
neutralized SL CoVs, i.e., bat-SL-
CoV strain WIVI (RBD with eight
amino acid differences from
SARS- Co) but not bat-SL-CoV
strain SHC014 (24 amino
acid differences) (200).
Appropriate RBD-specific MAbs
can be recognized by a relative
analvsis of RBD of SARS- CoV-2
to that of SARS-CoV, and cross-
neutralizing SARS-CoV RBD-
specific MAbs could be explored
for their effectiveness against
COVID-19 and further need to be
assessed clinically. The U.S.
biotechnology company
Regeneron is attempting to
recognize potent and specific
MAbs to combat COVID-19. An
ideal therapeutic option suggested
for SARS-CoV-2 (COVID-19) is
the combination therapy comprised
of MAbs and the drug remdesivir
(COVID-19) (201). The SARS-
CoV-specific human MAb
CR3022 is found to bind with
SARS-CoV-2
RBD, indicating its potential as a
therapeutic agent other clinical
trials in different phases are still
ongoing elsewhere.
Immunomodulatory agents. SARS-
CoV-2 triggers a strong immune
response which may cause
cytokine storm syndrome*. Thus,
immunomodulatory agents that
inhibit the excessive inflammatory
response may
be a potential adjunctive therapy
for COVID- 19. Dexamethasone is
a corticosteroid often used in a
wide range of conditions to relieve
inflammation through
its anti-inflammatory and
immunosuppressant effects.
Recently, the RECOVERY trial
found dexamethasone reduced
mortality by about one third in
hospitalized patients with COVID-
19 who received invasive mechan-
ical ventilation and by one fifth in
patients receiving oxygen. By
contrast, no benefit was found in
patients
without respiratory support'*.
Tocilizumab and sarilumab, two
types of interleukin-6 (IL.-6)
receptor-specific antibodies
previously used to treat various
types of arthritis, including
rheumatoid arthritis, and cytokine
release syndrome, showed effec-
tiveness in the treatment of severe
COVID- 19 by atten- uating the
cytokine storm in a small
uncontrolled trial 7, Bevacizumab
is an anti-vascular endothelial
growth factor (VEGI) medication
that could potentially reduce
pulmonary edema in patients with
severe COVID-19. Eculizumab is
a specific monoclonal antibody
that
inhibits the proinflammatory
complement protein C5.
Preliminary results showed that it
induced a drop of inflammatory
markers and C-reactive protein
levels, suggesting its potential to
be an option for the treatment of
severe COVID- 19 (REF. 149.

Been used based on the experience

with SARS and MERS. In a
historical control study in patients
with SARS, patients treated with
lopinavir- ritonavir with ribavirin
had better outcomes as compared
to those given
ribavirin alone [151. In the case
series of 99 hospitalized patients
with COVID-19 infection from
Wuhan, oxygen was given to 76%,
non-
invasive ventilation in 13%.
mechanical ventilation in 4%,
extracorporeal membrane
oxygenation
(ECMO) in 3%. continuous renal
replacement therapy (CRRT) in
9%, antibiotics in 71%, antifungals
in 15%, glucocorticoids in 19%
and intravenous
immunoglobulin therapy in 27%
[15]. Antiviral therapy consisting
of oseltamivir, ganciclovir and
lopinavir- ritonavir was given to
75% of the patients. The duration
of non-invasive
ventilation was 4-22 d (median 9
dj).
Cases of COVID-19 in countries
outside China were reported in
those with no history of travel to
China suggesting that local
human-to- human transmission
was occurring in these countries
{9]. Airports in different countries
including India put in screening
mechanisms to detect symptomatic
people returning from China and
placed them in isolation and
testing them for COVID-19. Soon
it was apparent that the infection
could be transmitted from
asymptomatic people
and also before onset of
symptoms. Therefore, countries
including India who evacuated
their citizens from Wuhan through
special flights or had travellers
returning from China, placed all
people symptomatic or otherwise
in
isolation for 14d and tested them
for the virus.

Guo Yanhong, an official with the

National Health Commission
(NHC), stated that convalescent
plasma therapy is a significant
method for treating severe
COVID-19 patients. Among the
COVID-19 patients currently
receiving convalescent plasma
therapy in the virus-hit Wuhan,
one has been discharged from
hospital, as reported by Chinese
science authorities on Monday,
17th February 2020 in Beijing.
The first dose of convalescent
plasma from a COVID-19 patient
was collected on 1st and 9th
February 2020 from a severely ill
patient who was given treatment at
a hospital in Jiangxia District in
Wuhan. The presence of the virus
in patients is minimised by the
antibodies in the convalescent
plasma. Guigiang stated that
donating plasma may cause
minimal harm to the donor and
that there is nothing to be worried
about. Plasma donors must be
cured patients and discharged from
hospital. Only plasma is used,
whereas red blood cells (RBC),
white blood cells (WBC) and
blood platelets are transfused back
into the donor's body. Wang
alleged that donor's plasma will
totally improve to its initial state
after one or 2 weeks from the
day of plasma donation of around
200 to 300 millilitres.
Prevention [21, 30]
Sinco at this time mere are no
approved treatments for this
infection,
prevention is crucial. several
properties of this virus make
prevention difficult namely, non-
specific features of the disease, the
infectivity even before onset of
symptoms in the incubation period,
transmission from asymptomatic
people, long incubation period,
tropism
 for mucosal surfaces such as the
conjunctiva, prolonged duration of
the
illness and transmission even after
clinical recovery. Isolation of
confirmed or suspected
cases with mild illness at home is
recommender The ventilation at
home should be good with sunlight
to allow for destruction of virus.
Patients should be asked to wear a
simple surgical
mask and practice cough hygiene.

prongs, face mask, high flow nasal

cannula (HFNC) or non-invasive
ventilation is indicated. Mechanical
ventilation and even extra corporeal
membrane oxygen support may be
needed. Renal replacement therapy may
be needed in some. Antibiotics
and antitungals are required it co
infections are suspected or proven. The
role of corticosteroids is unproven; while
current international consensus and
WHO advocate against their use, Chinese
guidelines do recommend short term
therapy with low-to- moderate dose
corticosteroids in COVID-19 ARDS (24,
25]. Detailed guidelines for critical care
management for COVID-19 have been
published by the WHO [26]. There is, as
of now, no approved treatment for
COVID-19. Antiviral drugs such as
ribavirin, lopinavir-ritonavir have been
used based on the experience
with SARS and MERS.
Bovine coronaviruses (BoCoVs) are
known to
infect several domestic and wild
ruminants (126). BoCoV inflicts neonatal
calf diarrhea in adult cattle, leading to
bloody diarrhea (winter dysentery) and
respiratory disease complex (shipping
fever) in cattle of all age groups (126).
BoCoV-like viruses have been noted in
humans, suggesting its zoonotic potential
as well (127). Feline enteric and feline
infectious peritonitis (FIP) viruses are the
two major feline CoVs (128), where
feline CoVs can affect the
gastrointestinal tract, abdominal cavity
(peritonitis),
respiratory tract, and central nervous
system (128). Canines are also affected
by Cos that fall under different genera,
namely, canine enteric coronavirus in
Alphacoronavirus and canine respiratory
coronavirus in Betacoronavirus, affecting
the enteric and respiratory tract,
respectively (129, 130). IBV, under
Gammacoronavirus, causes diseases of
respiratory, urinary, and reproductive
systems, with
substantial economic losses in chickens
(131, 132). In small laboratory animals,
mouse hepatitis virus. rat
sialodacryoadenitis coronavirus, and
guinea pig and rabbit coronaviruses are
the major Cos associated with disease
manifestations like enteritis.
hepatitis, and respiratory infections (10,
133).

The virus can remain viable on surfaces

for days in favourable atmospheric
conditions but are destroyed in less than
a minute by common disinfectants like
sodium
hypochlorite, hydrogen peroxide etc.
[13]. Infection is acquired either by
inhalation of these droplets or touching
surfaces contaminated by them and then
touching the nose, mouth and eyes. The
virus is also present in the stool and
contamination of the water supply and
subsequent transmission via
aerosolization/feco oral route is also
hypothesized (6]. As per current
information, transplacental transmission
from pregnant women to
their fetus has not been described [14].
However, neonatal disease due to post
natal transmission is described [141. The
incubation period varies from 2 to 14 d
[median 5 d].
Cases continued to increase
exponentially and modelling studies
reported an epidemic doubling time of
1.8 d [101. In fact on the 12th of
February, China changed its definition of
confirmed cases to include patients with
negative/ pending molecular tests but
with clinical, radiologic and
epidemiologic features of COVID-19
leading to an increase in cases by
15,000 in a single day (6]. As of
05/03/2020 96.000 cases worldwide
(80,000 in China) and 87 other countries
and 1 international conveyance (696, in
the cruise ship Diamond Princess parked
off the coast of lapan) have been reported
[2]. It is important to note that while the
number of new cases has reduced in
China lately, they have increased
exponentially in other countries
including South Korea, Italy and Iran.
Of those infected, 20% are in critical
And comprised a small population and.
hence. the possibility of misinterpretation
could arise. However,
in another case study, the authors raised
concerns
overthe
efficacy of hydroxychloroquine-
azithromyein in the treatment of COVID-
19 patients, since no observable effect
was seen when they were used. In some
cases, the treatment was discontinued
due to the prolongation of the QT
interval (307). Hence, further
randomized clinical trials are required
before concluding this matter.
Recently, another FDA-approved
drug, ivermectin, was reported to inhibit
the in vitro replication of SARS-CoV-2.
The findings from this study indicate that
a single treatment of this drug was able
to induce an -5.000-fold reduction in the
viral RNA at 48 h in cell culture. (308).
One of the main disadvantages that limit
the clinical utility of
ivermectin is its potential to cause
cytotoxicity. However, altering the
vehicles used in the formulations, the
pharmacokinetic properties can be
modified, thereby having significant
control over the systemic concentration
of ivermectin (338). Based on the
pharmacokinetic simulation, it was also
found that ivermectin may have limited
therapeutic utility in managing COVID-
19, since the inhibitory concentration that
has to be achieved for effective
anti-SARS-CoV-2 activity is far higher
than the was linked to a family member
and 26 children had history of
travel/residence to Hubei province in
China. All the patients were either
asymptomatic (9%) or had mild disease.
No severe or critical cases were seen.
The most common symptoms were fever
(50%) and cough (38%). All patients
recovered with symptomatic therapy and
there were no deaths. One case of severe
pneumonia and multiorgan dysfunction
in a child has also been
reported (191. Similarly the neonatal
cases that have been reported have
been mild (20].

Diagnosis [21] A suspect case is defined

as one with fever, sore throat and cough
who has history of travel to China or
other areas of persistent local
transmission or
contact with patients with similar
travel history or those with confirmed
of persistent local transmission or contact
with patients with similar
travel history or those with confirmed
COVID-19 infection. However cases
may be asymptomatic or even without
fever. A confirmed case is a suspect
case with a positive molecular test.
Specific diagnosis is by specific
molecular tests on respiratory samples
(throat swab/ nasopharyngeal swab/
sputum/ endotracheal aspirates and
bronchoalveolar lavage). Virus may
also be detected in the stool and in
soverp cases the blood.it must he
remembered that the multiplex PCR
panels currently available do not include
the COVID-19. Commercial tests are
also not available at present. In a suspect
case in India, the appropriate sample has
to be sent to designated
reference labs in India or the National
Institute of Virology in Pune. As the
epidemic progresses, commercial tests
identified angiotensin receptor 2 (ACE,)
as the receptor through which the virus
enters the respiratory mucosa
(11). The basic case reproduction rate
(BCR) is estimated to range from 2 to
6.47 in various modelling studies [11]. In
comparison, the BCR of SARS was 2
and
1.3 for pandemic flu H1N1 2009 [2].

Coronaviruses are a family of viruses that can cause illnesses such as the common
cold, severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome
(MERS). In 2019, a new coronavirus was identified as the cause of a disease outbreak
that originated in China.
The virus is known as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).
The disease it causes is called coronavirus disease 2019 (COVID-19). In March 2020,
the World Health Organization (WHO) declared the COVID-19 outbreak a pandemic.
Public health groups, including the U.S. Centers for Disease Control and Prevention
(CDC) and WHO, are monitoring the COVID-19 pandemic and posting updates on their
websites. These groups have also issued recommendations for preventing and treating
the virus that causes COVID-19.

Symptoms
Signs and symptoms of coronavirus disease 2019 (COVID-19) may appear 2 to 14 days
after exposure. This time after exposure and before having symptoms is called the
incubation period. You can still spread COVID-19 before you have symptoms
(presymptomatic transmission). Common signs and symptoms can include:

 Fever
 Cough
 Tiredness
Early symptoms of COVID-19 may include a loss of taste or smell.
Other symptoms can include:

 Shortness of breath or difficulty breathing

 Muscle aches
 Chills
 Sore throat
 Runny nose
 Headache
 Chest pain
 Pink eye (conjunctivitis)
 Nausea
 Vomiting
 Diarrhea
 Rash
This list isn't complete. Children have similar symptoms to adults and generally have
mild illness.
The severity of COVID-19 symptoms can range from very mild to severe. Some people
may have only a few symptoms. Some people may have no symptoms at all, but can
still spread it (asymptomatic transmission). Some people may experience worsened
symptoms, such as worsened shortness of breath and pneumonia, about a week after
symptoms start.
Some people experience COVID-19symptoms for more than four weeks after they're
diagnosed. These health issues are sometimes called post-COVID-19 conditions. Some
children experience multisystem inflammatory syndrome, a syndrome that can affect
some organs and tissues, several weeks after having COVID-19. Rarely, some adults
experience the syndrome too.
People who are older have a higher risk of serious illness from COVID-19, and the risk
increases with age. People who have existing medical conditions also may have a
higher risk of serious illness. Certain medical conditions that may increase the risk of
serious illness from COVID-19 include:

 Serious heart diseases, such as heart failure, coronary artery disease or

cardiomyopathy
 Cancer
 Chronic obstructive pulmonary disease (COPD)
 Type 1 or type 2 diabetes
 Overweight, obesity or severe obesity
 High blood pressure
 Smoking
 Chronic kidney disease
 Sickle cell disease or thalassemia
 Weakened immune system from solid organ transplants or bone marrow
transplants
 Pregnancy
 Asthma
 Chronic lung diseases such as cystic fibrosis or pulmonary hypertension
 Liver disease
 Dementia
 Down syndrome
 Weakened immune system from bone marrow transplant, HIV or some
medications
  Brain and nervous system conditions, such as strokes
 Substance use disorders
This list is not complete. Other medical conditions may increase your risk of serious
illness from COVID-19.

When to see a doctor

If you have COVID-19 signs or symptoms or you've been in contact with someone
diagnosed with COVID-19, contact your health care provider right away for medical
advice. Your health care provider will likely recommend that you get tested for COVID-
19. If you have emergency COVID-19 symptoms, such as trouble breathing, seek care
immediately. If you need to go to a hospital, call ahead so that health care providers can
take steps to ensure that others aren't exposed.
If you have emergency COVID-19 signs and symptoms, seek care immediately.
Emergency signs and symptoms can include:

 Trouble breathing
 Persistent chest pain or pressure
 Inability to stay awake
 New confusion
 Pale, gray or blue-colored skin, lips or nail beds — depending on skin tone
This list isn't complete. Let your health care provider know if you are an older adult or
have chronic medical conditions, such as heart disease or lung disease, as you may
have a greater risk of becoming seriously ill with COVID-19

Causes
Infection with severe acute respiratory syndrome coronavirus 2, or SARS-CoV-2,
causes coronavirus disease 2019 (COVID-19).
The virus that causes COVID-19 spreads easily among people. Data has shown that
the COVID-19 virus spreads mainly from person to person among those in close
contact. The virus spreads by respiratory droplets released when someone with the
virus coughs, sneezes, breathes, sings or talks. These droplets can be inhaled or land
in the mouth, nose or eyes of a person nearby.
Sometimes the COVID-19 virus can spread when a person is exposed to very small
droplets or aerosols that stay in the air for several minutes or hours — called airborne
transmission.
The virus can also spread if you touch a surface with the virus on it and then touch your
mouth, nose or eyes. But the risk is low.
The COVID-19 virus can spread from someone who is infected but has no symptoms.
This is called asymptomatic transmission. The COVID-19 virus can also spread from
someone who is infected but hasn't developed symptoms yet. This is called
presymptomatic transmission.
It's possible to get COVID-19 more than once.

Risk factors
Risk factors for COVID-19 appear to include:

 Close contact with someone who has COVID-19, especially someone with
symptoms
 Being coughed or sneezed on by an infected person
 Being near an infected person when in an indoor space with poor air flow

Complications
Although most people with COVID-19 have mild to moderate symptoms, the disease
can cause severe medical complications and lead to death in some people. Older adults
or people with existing medical conditions are at greater risk of becoming seriously ill
with COVID-19.
Complications can include:

 Pneumonia and trouble breathing

 Organ failure in several organs
 Heart problems
 A severe lung condition that causes a low amount of oxygen to go through
your bloodstream to your organs (acute respiratory distress syndrome)
 Blood clots
 Acute kidney injury
 Additional viral and bacterial infections
The U.S. Food and Drug Administration (FDA) has given emergency use authorization
to some COVID-19 vaccines in the United States. The FDA has approved the Pfizer-
BioNTech COVID-19 vaccine, now called Comirnaty, to prevent COVID-19 in people
age 12 and older. The FDA has given emergency use authorization to Pfizer-
BioNTech COVID-19 vaccines for ages 6 months through 11.
The FDA has approved the Moderna vaccine, now called Spikevax, to prevent COVID-
19 in people age 18 and older. The FDA has also authorized the Moderna COVID-
19 vaccine in children ages 6 months through 17 years old. The FDA has also
authorized the Novavax COVID-19, adjuvanted vaccine to prevent COVID-19 in people
age 12 and older.
Due to the risk of a potentially life-threatening blood-clotting problem, the FDA is
restricting use of the Janssen/Johnson & Johnson vaccine to certain people age 18 and
older. Examples include people who had a severe allergic reaction after getting
an mRNACOVID-19 vaccine and people who can't get an mRNA COVID-19 vaccine
due to limited access or personal or religious concerns. If you get this vaccine, be sure
to understand the risks and symptoms of the blood-clotting problem.
A vaccine can prevent you from getting the COVID-19 virus or prevent you from
becoming seriously ill if you get the COVID-19virus. In addition, COVID-19 vaccination
might offer better protection than getting sick with COVID-19. A recent study showed
that unvaccinated people who already had COVID-19 are more than twice as likely as
fully vaccinated people to get reinfected with COVID-19.
After getting vaccinated, you can more safely return to many activities you may not have
been able to do because of the pandemic. However, if you are in an area with a high
number of people with COVID-19 in the hospital and new COVID-19 cases,
the CDCrecommends wearing a mask indoors in public. You're considered fully
vaccinated two weeks after you get a second dose of an mRNA COVID-19 vaccine,
after two doses of the Novavax vaccine, or two weeks after you get a single dose of the
Janssen/Johnson & Johnson COVID-19 vaccine. You are considered up to date with
your vaccines if you have gotten all recommended COVID-19vaccines, including
booster doses, when you become eligible.
An additional primary dose of a COVID-19vaccine is recommended for people who are
vaccinated and might not have had a strong enough immune response.
In contrast, a booster dose is recommended for people who are vaccinated and whose
immune response weakened over time. Research suggests that getting a booster dose
can decrease your risk of infection and severe illness with COVID-19.
People who have a moderately or severely weakened immune system should get an
additional primary shot and a booster shot.
The CDC recommends additional doses and booster doses of COVID-19 vaccines in
specific instances:
 Additional primary shot. The CDCrecommends an additional primary shot
of an mRNA COVID-19 vaccine for some people with weakened immune
 systems, such as those who have had an organ transplant. People with
weakened immune systems might not develop enough immunity after
vaccination with two doses of an mRNA COVID-19 vaccine or one dose of
the Janssen/Johnson & Johnson COVID-19 vaccine. An additional shot
using an mRNA COVID-19 vaccine might improve their protection
against COVID-19. This recommendation for an additional mRNA COVID-
19 shot is for people ages 6 months and older.
The additional primary shot should be given at least four weeks after a
second dose of an mRNA COVID-19 vaccine or one dose of the
Janssen/Johnson & Johnson COVID-19 vaccine. The additional primary
shot should be the same brand as the other two mRNACOVID-19 vaccine
doses that were given. If the brand given isn't known, either brand
of mRNA COVID-19 vaccine can be given as a third dose.
 Booster dose. These recommendations differ by age, what vaccines you
have been given and the state of your immune system. But in general,
people can get the booster shot at least two months after their last shot.
People who recently had a positive COVID-19 test may think about waiting
three months after their symptoms started to get the booster.
Kids ages 6 months through 4 years who got the Moderna COVID-
19 vaccine can only get an updated, called bivalent, Moderna COVID-
19 vaccine booster. The booster is based on the original virus strain and two
omicron strains.
Kids age 6 months through 5 years who got the Pfizer-BioNTech COVID-
19vaccine can only get the updated Pfizer-BioNTech booster. The booster
is based on the original virus strain and two omicron strains.
People age 5 and older who got the Moderna COVID-19 vaccine, and
people age 6 and older who got either vaccine can choose between the
updated Pfizer-BioNTech and the updated Moderna COVID-19 bivalent
vaccine boosters.
People age 12 and older who got the Novavax COVID-19 vaccine can
choose between the updated Pfizer-BioNTech and the updated
Moderna COVID-19bivalent vaccine boosters.
If you are age 18 or older, and got the Janssen COVID-19 vaccine, you can
get either of the mRNA vaccine bivalent boosters at least two months after
your shot. People 18 and older may also get a Novavax booster based on
the original virus strain as a first booster at least six months after their last
shot.
Pregnant people can also get a COVID-19booster dose.
There are many steps you can take to reduce your risk of infection from the COVID-
19 virus and reduce the risk of spreading it to others. WHO and CDC recommend
following these precautions:
  Get vaccinated. COVID-19 vaccines reduce the risk of getting and
spreading COVID-19.
 Avoid close contact with anyone who is sick or has symptoms.
 Keep distance between yourself and others when you're in indoor public
spaces. This is especially important if you have a higher risk of serious
illness. Keep in mind some people may have COVID-19and spread it to
others, even if they don't have symptoms or don't know they have COVID-
19.
 Avoid crowds and indoor places that have poor air flow (ventilation).
 Wash your hands often with soap and water for at least 20 seconds, or use
an alcohol-based hand sanitizer that contains at least 60% alcohol.
 Wear a face mask in indoor public spaces if you're in an area with a high
number of people with COVID-19 in the hospital and new COVID-19 cases,
whether or not you're vaccinated. The CDC recommends wearing the most
protective mask possible that you'll wear regularly, fits well and is
comfortable.
 Improve the air flow indoors. Open windows. Turn on fans to direct air out of
windows. If you can't open windows, consider using air filters. And turn on
exhaust fans in your bathroom and kitchen. You might also consider a
portable air cleaner.
 Cover your mouth and nose with your elbow or a tissue when you cough or
sneeze. Throw away the used tissue. Wash your hands right away.
 Avoid touching your eyes, nose and mouth.
 Avoid sharing dishes, glasses, towels, bedding and other household items if
you're sick.
 Clean and disinfect high-touch surfaces, such as doorknobs, light switches,
electronics and counters, regularly.
 Stay home from work, school and public areas and stay home in isolation if
you're sick, unless you're going to get medical care. Avoid public
transportation, taxis and ride-hailing services if you're sick.
If you have a chronic medical condition and may have a higher risk of serious illness,
check with your doctor about other ways to protect yourself.

COVID-19 spreads when an infected person breathes out droplets and

very small particles that contain the virus. Other people can breathe in
these droplets and particles, or these droplets and particles can land
on their eyes, nose, or mouth. In some circumstances, these droplets
may contaminate surfaces they touch.

Anyone infected with COVID-19 can spread it, even if they do NOT
have symptoms.

The risk of animals spreading the virus that causes COVID-19 to people
is low. The virus can spread from people to animals during close
contact. People with suspected or confirmed COVID-19 should avoid
contact with animals.

What are antibodies and how do they help

protect me?
Antibodies are proteins your immune system makes to help fight infection and protect you from
getting sick in the future. A positive antibody test result can help identify someone who has had
COVID-19 in the past or has been vaccinated against COVID-19. Studies show that people who
have antibodies from an infection with the virus that causes COVID-19 can improve their level
of protection by getting vaccinated

What are ways to prevent COVID-19?

There are many actions you can take to help protect you, your
household, and your community from COVID-19. CDC’s COVID-19
hospital admission levels help individuals and communities decide
when to take action to protect yourself and others based on the latest
data and information from your area.

In addition to staying up to date with COVID-19 vaccines and basic

health and hygiene practices like handwashing, CDC recommends
some prevention actions at all COVID-19 hospital admission levels.

Who is at risk of severe illness from COVID-

19?
Some people are more likely than others to get very sick if they get
COVID-19. This includes people who are older,
are immunocompromised, have certain disabilities, or have underlying
health conditions. Understanding your COVID-19 risk and the risks that
might affect others can help you make decisions to protect yourself
and others.

What are variants of COVID-19?

Viruses are constantly changing, including the virus that causes
COVID-19. These changes occur over time and can lead to new strains
of the virus or variants of COVID-19 . Slowing the spread of the virus,
by protecting yourself and others, can help slow new variants from
developing. CDC is working with state and local public health officials
to monitor the spread of all variants, including Omicron.

How does the coronavirus spread?

As of now, researchers know that the coronavirus is spread through droplets and
virus particles released into the air when an infected person breathes, talks,
laughs, sings, coughs or sneezes. Larger droplets may fall to the ground in a few
seconds, but tiny infectious particles can linger in the air and accumulate in indoor
places, especially where many people are gathered and there is poor ventilation.
This is why mask-wearing, hand hygiene and physical distancing are essential to
preventing COVID-19.

How did the coronavirus start?

The first case of COVID-19 was reported Dec. 1, 2019, and the cause was a then-
new coronavirus later named SARS-CoV-2. SARS-CoV-2 may have originated in an
animal and changed (mutated) so it could cause illness in humans. In the past,
several infectious disease outbreaks have been traced to viruses originating in
birds, pigs, bats and other animals that mutated to become dangerous to humans.
Research continues, and more study may reveal how and why the coronavirus
evolved to cause pandemic disease.

What is the incubation period for COVID-19?

Symptoms show up in people within two to 14 days of exposure to the virus. A

person infected with the coronavirus is contagious to others for up to two days
before symptoms appear, and they remain contagious to others for 10 to 20 days,
depending upon their immune system and the severity of their illness.

Some people infected with the coronavirus have mild COVID-19 illness, and others
have no symptoms at all. In some cases, however, COVID-19 can lead to
respiratory failure, lasting lung and heart muscle damage, nervous system
problems, kidney failure or death.

If you have a fever or any of the symptoms listed above, call your doctor or a
health care provider and explain your symptoms over the phone before going to
the doctor’s office, urgent care facility or emergency room. Here are suggestions if
you feel sick and are concerned you might have COVID-19.

How is COVID-19 diagnosed?

COVID-19 is diagnosed through a test. Diagnosis by examination alone is difficult

since many COVID-19 signs and symptoms can be caused by other illnesses. Some
people with the coronavirus do not have symptoms at all. Learn more about
COVID-19 testing.

How is COVID-19 treated?

Treatment for COVID-19 depends on the severity of the infection. For milder
illness, resting at home and taking medicine to reduce fever is often sufficient.
More severe cases may require hospitalization, with treatment that might include
intravenous medications, supplemental oxygen, assisted ventilation and other
supportive measures

How do you protect yourself from this?

There are several COVID-19 vaccines recommended by the CDC. It is also

important to receive a booster when you are eligible.

In addition, it helps to keep up with other safety precautions, such as following

testing guidelines, wearing a mask, washing your hands and practicing physical
distancing.

Does COVID-19 cause death?

Yes, severe COVID-19 can be fatal. For updates of coronavirus infections, deaths
and vaccinations worldwide, see the Coronavirus COVID-19 Global Cases map
developed by the Johns Hopkins Center for Systems Science and Engineering.

Two COVID-19 vaccines – Pfizer and Moderna - have been fully approved by the
FDA and recommended by the CDC as highly effective in preventing serious
disease, hospitalization and death from COVID-19.

The CDC notes that in most situations the two mRNA vaccines from Pfizer and
Moderna are preferred over the Johnson & Johnson vaccine due to a risk of serious
adverse events.
It is also important to receive a booster when eligible. You can get any of these
three authorized or approved vaccines, but the CDC explains that Pfizer and
Moderna are preferred in most situations.

Why is it called coronavirus?

Coronaviruses are named for their appearance: “corona” means “crown.” The
virus’s outer layers are covered with spike proteins that surround them like a
crown.

Is this coronavirus different from SARS?

SARS stands for severe acute respiratory syndrome. In 2003, an outbreak of SARS
affected people in several countries before ending in 2004. The coronavirus that
causes COVID-19 is similar to the one that caused the 2003 SARS outbreak.

Since the 2019 coronavirus is related to the original coronavirus that caused SARS
and can also cause severe acute respiratory syndrome, there is “SARS” in its name:
SARS-CoV-2. Much is still unknown about these viruses, but SARS-CoV-2 spreads
faster and farther than the 2003 SARS-CoV-1 virus. This is likely because of how
easily it is transmitted person to person, even from asymptomatic carriers of the
virus.

Are there different variants of this coronavirus?

Yes, there are different variants of this coronavirus. Like other viruses, the
coronavirus that causes COVID-19 can change (mutate). Mutations may enable the
coronavirus to spread faster from person to person as in the case of the delta and
omicron variants. More infections can result in more people getting very sick and
also create more opportunity for the virus to develop further mutations. Read
more about coronavirus variants.
OVERVIEW
Coronavirus disease 2019 (COVID-19) is a virus identified as the cause of an outbreak of
respiratory illness.

What is coronavirus?
Coronaviruses are a family of viruses that can cause respiratory illness in
humans. They are called “corona” because of crown-like spikes on the
surface of the virus. Severe acute respiratory syndrome (SARS), Middle East
respiratory syndrome (MERS) and the common cold are examples of
coronaviruses that cause illness in humans.

The new strain of coronavirus — SARS-CoV-2 — was first reported in

Wuhan, China in December 2019. It has since spread to every country
around the world.

Cleveland Clinic is a non-profit academic medical center. Advertising on

our site helps support our mission. We do not endorse non-Cleveland
Clinic products or services. Policy

Where do coronaviruses come from?

Coronaviruses are often found in bats, cats and camels. The viruses live in
but don’t infect the animals. Sometimes these viruses then spread to
different animal species. The viruses may change (mutate) as they transfer
to other species. Eventually, the virus can jump from animal species and
begin to infect humans. In the case of SARS-CoV-19, the first people
infected are thought to have contracted the virus at a food market that
sold meat, fish and live animals.

How do you get COVID-19?

SARS-CoV-2, the virus that causes COVID-19, enters your body through
your mouth, nose or eyes (directly from the airborne droplets or from the
transfer of the virus from your hands to your face). It then travels to the
back of your nasal passages and mucous membrane in the back of your
throat. It attaches to cells there, begins to multiply and moves into lung
tissue. From there, the virus can spread to other body tissues.
How does the new coronavirus (SARS-CoV-2) spread from person to person?

Coronavirus is likely spread:

  The virus travels in respiratory droplets released into the air when an
infected person coughs, sneezes, talks, sings or breathes near you.
You may be infected if you inhale these droplets.
 You can also get coronavirus from close contact (touching, shaking
hands) with an infected person and then touching your face.

How long is a person with COVID-19 considered contagious?

If you have COVID-19 it can take several days to develop symptoms — but
you’re contagious during this time. You are no longer contagious 10 days
after your symptoms began.

The best way to avoid spreading COVID-19 to others is to:

 Stay 6 feet away from others whenever possible.

 Wear a cloth mask that covers your mouth and nose when around
others.
 Wash your hands often. If soap isn’t available, use a hand sanitizer
that contains at least 60% alcohol.
 Avoid crowded indoor spaces. Open windows to bring in outdoor air
as much as possible.
 Stay self-isolated at home if you are feeling ill with symptoms that
could be COVID-19 or have a positive test for COVID-19.
 Clean and disinfect frequently touched surfaces.

Who’s most at risk for getting COVID-19?

Persons at greatest risk of contracting COVID-19 include those who:

 Live in or have recently traveled to any area with ongoing active

spread.
 Have had close contact with a person who has a laboratory-
confirmed or a suspected case of the COVID-19 virus. Close contact is
defined as being within 6 feet of an infected person for
a cumulative total of 15 minutes or more over a 24-hour period.
  Are over the age of 60 with pre-existing medical conditions or a
weakened immune system.
Coronaviruses are a family of viruses that can cause illnesses such as the common
cold, severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome
(MERS). In 2019, a new coronavirus was identified as the cause of a disease outbreak
that originated in China.
The virus is known as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).
The disease it causes is called coronavirus disease 2019 (COVID-19). In March 2020,
the World Health Organization (WHO) declared the COVID-19 outbreak a pandemic.
Public health groups, including the U.S. Centers for Disease Control and Prevention
(CDC) and WHO, are monitoring the COVID-19 pandemic and posting updates on their
websites. These groups have also issued recommendations for preventing and treating
the virus that causes COVID-19.

Symptoms
Signs and symptoms of coronavirus disease 2019 (COVID-19) may appear 2 to 14 days
after exposure. This time after exposure and before having symptoms is called the
incubation period. You can still spread COVID-19 before you have symptoms
(presymptomatic transmission). Common signs and symptoms can include:

 Fever
 Cough
 Tiredness
Early symptoms of COVID-19 may include a loss of taste or smell.
Other symptoms can include:

 Shortness of breath or difficulty breathing

 Muscle aches
 Chills
 Sore throat
 Runny nose
 Headache
 Chest pain
  Pink eye (conjunctivitis)
 Nausea
 Vomiting
 Diarrhea
 Rash
This list isn't complete. Children have similar symptoms to adults and generally have
mild illness.
The severity of COVID-19 symptoms can range from very mild to severe. Some people
may have only a few symptoms. Some people may have no symptoms at all, but can
still spread it (asymptomatic transmission). Some people may experience worsened
symptoms, such as worsened shortness of breath and pneumonia, about a week after
symptoms start.
Some people experience COVID-19symptoms for more than four weeks after they're
diagnosed. These health issues are sometimes called post-COVID-19 conditions. Some
children experience multisystem inflammatory syndrome, a syndrome that can affect
some organs and tissues, several weeks after having COVID-19. Rarely, some adults
experience the syndrome too.
People who are older have a higher risk of serious illness from COVID-19, and the risk
increases with age. People who have existing medical conditions also may have a
higher risk of serious illness. Certain medical conditions that may increase the risk of
serious illness from COVID-19 include:

 Serious heart diseases, such as heart failure, coronary artery disease or

cardiomyopathy
 Cancer
 Chronic obstructive pulmonary disease (COPD)
 Type 1 or type 2 diabetes
 Overweight, obesity or severe obesity
 High blood pressure
 Smoking
 Chronic kidney disease
 Sickle cell disease or thalassemia
 Weakened immune system from solid organ transplants or bone marrow
transplants
 Pregnancy
  Asthma
 Chronic lung diseases such as cystic fibrosis or pulmonary hypertension
 Liver disease
 Dementia
 Down syndrome
 Weakened immune system from bone marrow transplant, HIV or some
medications
 Brain and nervous system conditions, such as strokes
 Substance use disorders
This list is not complete. Other medical conditions may increase your risk of serious
illness from COVID-19.

When to see a doctor

If you have COVID-19 signs or symptoms or you've been in contact with someone
diagnosed with COVID-19, contact your health care provider right away for medical
advice. Your health care provider will likely recommend that you get tested for COVID-
19. If you have emergency COVID-19 symptoms, such as trouble breathing, seek care
immediately. If you need to go to a hospital, call ahead so that health care providers can
take steps to ensure that others aren't exposed.
If you have emergency COVID-19 signs and symptoms, seek care immediately.
Emergency signs and symptoms can include:

 Trouble breathing
 Persistent chest pain or pressure
 Inability to stay awake
 New confusion
 Pale, gray or blue-colored skin, lips or nail beds — depending on skin tone
This list isn't complete. Let your health care provider know if you are an older adult or
have chronic medical conditions, such as heart disease or lung disease, as you may
have a greater risk of becoming seriously ill with COVID-19

Causes
Infection with severe acute respiratory syndrome coronavirus 2, or SARS-CoV-2,
causes coronavirus disease 2019 (COVID-19).
The virus that causes COVID-19 spreads easily among people. Data has shown that
the COVID-19 virus spreads mainly from person to person among those in close
contact. The virus spreads by respiratory droplets released when someone with the
virus coughs, sneezes, breathes, sings or talks. These droplets can be inhaled or land
in the mouth, nose or eyes of a person nearby.
Sometimes the COVID-19 virus can spread when a person is exposed to very small
droplets or aerosols that stay in the air for several minutes or hours — called airborne
transmission.
The virus can also spread if you touch a surface with the virus on it and then touch your
mouth, nose or eyes. But the risk is low.
The COVID-19 virus can spread from someone who is infected but has no symptoms.
This is called asymptomatic transmission. The COVID-19 virus can also spread from
someone who is infected but hasn't developed symptoms yet. This is called
presymptomatic transmission.
It's possible to get COVID-19 more than once.

Risk factors
Risk factors for COVID-19 appear to include:

 Close contact with someone who has COVID-19, especially someone with
symptoms
 Being coughed or sneezed on by an infected person
 Being near an infected person when in an indoor space with poor air flow

Complications
Although most people with COVID-19 have mild to moderate symptoms, the disease
can cause severe medical complications and lead to death in some people. Older adults
or people with existing medical conditions are at greater risk of becoming seriously ill
with COVID-19.
Complications can include:

 Pneumonia and trouble breathing

 Organ failure in several organs
 Heart problems
  A severe lung condition that causes a low amount of oxygen to go through
your bloodstream to your organs (acute respiratory distress syndrome)
 Blood clots
 Acute kidney injury
 Additional viral and bacterial infections

The U.S. Food and Drug Administration (FDA) has given emergency use authorization
to some COVID-19 vaccines in the United States. The FDA has approved the Pfizer-
BioNTech COVID-19 vaccine, now called Comirnaty, to prevent COVID-19 in people
age 12 and older. The FDA has given emergency use authorization to Pfizer-
BioNTech COVID-19 vaccines for ages 6 months through 11.
The FDA has approved the Moderna vaccine, now called Spikevax, to prevent COVID-
19 in people age 18 and older. The FDA has also authorized the Moderna COVID-
19 vaccine in children ages 6 months through 17 years old. The FDA has also
authorized the Novavax COVID-19, adjuvanted vaccine to prevent COVID-19 in people
age 12 and older.
Due to the risk of a potentially life-threatening blood-clotting problem, the FDA is
restricting use of the Janssen/Johnson & Johnson vaccine to certain people age 18 and
older. Examples include people who had a severe allergic reaction after getting
an mRNACOVID-19 vaccine and people who can't get an mRNA COVID-19 vaccine
due to limited access or personal or religious concerns. If you get this vaccine, be sure
to understand the risks and symptoms of the blood-clotting problem.
A vaccine can prevent you from getting the COVID-19 virus or prevent you from
becoming seriously ill if you get the COVID-19virus. In addition, COVID-19 vaccination
might offer better protection than getting sick with COVID-19. A recent study showed
that unvaccinated people who already had COVID-19 are more than twice as likely as
fully vaccinated people to get reinfected with COVID-19.
After getting vaccinated, you can more safely return to many activities you may not have
been able to do because of the pandemic. However, if you are in an area with a high
number of people with COVID-19 in the hospital and new COVID-19 cases,
the CDCrecommends wearing a mask indoors in public. You're considered fully
vaccinated two weeks after you get a second dose of an mRNA COVID-19 vaccine,
after two doses of the Novavax vaccine, or two weeks after you get a single dose of the
Janssen/Johnson & Johnson COVID-19 vaccine. You are considered up to date with
your vaccines if you have gotten all recommended COVID-19vaccines, including
booster doses, when you become eligible.
An additional primary dose of a COVID-19vaccine is recommended for people who are
vaccinated and might not have had a strong enough immune response.
In contrast, a booster dose is recommended for people who are vaccinated and whose
immune response weakened over time. Research suggests that getting a booster dose
can decrease your risk of infection and severe illness with COVID-19.
People who have a moderately or severely weakened immune system should get an
additional primary shot and a booster shot.
The CDC recommends additional doses and booster doses of COVID-19 vaccines in
specific instances:
 Additional primary shot. The CDCrecommends an additional primary shot
of an mRNA COVID-19 vaccine for some people with weakened immune
systems, such as those who have had an organ transplant. People with
weakened immune systems might not develop enough immunity after
vaccination with two doses of an mRNA COVID-19 vaccine or one dose of
the Janssen/Johnson & Johnson COVID-19 vaccine. An additional shot
using an mRNA COVID-19 vaccine might improve their protection
against COVID-19. This recommendation for an additional mRNA COVID-
19 shot is for people ages 6 months and older.
The additional primary shot should be given at least four weeks after a
second dose of an mRNA COVID-19 vaccine or one dose of the
Janssen/Johnson & Johnson COVID-19 vaccine. The additional primary
shot should be the same brand as the other two mRNACOVID-19 vaccine
doses that were given. If the brand given isn't known, either brand
of mRNA COVID-19 vaccine can be given as a third dose.
 Booster dose. These recommendations differ by age, what vaccines you
have been given and the state of your immune system. But in general,
people can get the booster shot at least two months after their last shot.
People who recently had a positive COVID-19 test may think about waiting
three months after their symptoms started to get the booster.
Kids ages 6 months through 4 years who got the Moderna COVID-
19 vaccine can only get an updated, called bivalent, Moderna COVID-
19 vaccine booster. The booster is based on the original virus strain and two
omicron strains.
Kids age 6 months through 5 years who got the Pfizer-BioNTech COVID-
19vaccine can only get the updated Pfizer-BioNTech booster. The booster
is based on the original virus strain and two omicron strains.
People age 5 and older who got the Moderna COVID-19 vaccine, and
people age 6 and older who got either vaccine can choose between the
updated Pfizer-BioNTech and the updated Moderna COVID-19 bivalent
vaccine boosters.
People age 12 and older who got the Novavax COVID-19 vaccine can
choose between the updated Pfizer-BioNTech and the updated
Moderna COVID-19bivalent vaccine boosters.
 If you are age 18 or older, and got the Janssen COVID-19 vaccine, you can
get either of the mRNA vaccine bivalent boosters at least two months after
your shot. People 18 and older may also get a Novavax booster based on
the original virus strain as a first booster at least six months after their last
shot.
Pregnant people can also get a COVID-19booster dose.
There are many steps you can take to reduce your risk of infection from the COVID-
19 virus and reduce the risk of spreading it to others. WHO and CDC recommend
following these precautions:

 Get vaccinated. COVID-19 vaccines reduce the risk of getting and

spreading COVID-19.
 Avoid close contact with anyone who is sick or has symptoms.
 Keep distance between yourself and others when you're in indoor public
spaces. This is especially important if you have a higher risk of serious
illness. Keep in mind some people may have COVID-19and spread it to
others, even if they don't have symptoms or don't know they have COVID-
19.
 Avoid crowds and indoor places that have poor air flow (ventilation).
 Wash your hands often with soap and water for at least 20 seconds, or use
an alcohol-based hand sanitizer that contains at least 60% alcohol.
 Wear a face mask in indoor public spaces if you're in an area with a high
number of people with COVID-19 in the hospital and new COVID-19 cases,
whether or not you're vaccinated. The CDC recommends wearing the most
protective mask possible that you'll wear regularly, fits well and is
comfortable.
 Improve the air flow indoors. Open windows. Turn on fans to direct air out of
windows. If you can't open windows, consider using air filters. And turn on
exhaust fans in your bathroom and kitchen. You might also consider a
portable air cleaner.
 Cover your mouth and nose with your elbow or a tissue when you cough or
sneeze. Throw away the used tissue. Wash your hands right away.
 Avoid touching your eyes, nose and mouth.
 Avoid sharing dishes, glasses, towels, bedding and other household items if
you're sick.
 Clean and disinfect high-touch surfaces, such as doorknobs, light switches,
electronics and counters, regularly.
  Stay home from work, school and public areas and stay home in isolation if
you're sick, unless you're going to get medical care. Avoid public
transportation, taxis and ride-hailing services if you're sick.
If you have a chronic medical condition and may have a higher risk of serious illness,
check with your doctor about other ways to protect yourself.

COVID-19 spreads when an infected person breathes out droplets and

very small particles that contain the virus. Other people can breathe in
these droplets and particles, or these droplets and particles can land
on their eyes, nose, or mouth. In some circumstances, these droplets
may contaminate surfaces they touch.

Anyone infected with COVID-19 can spread it, even if they do NOT
have symptoms.

The risk of animals spreading the virus that causes COVID-19 to people
is low. The virus can spread from people to animals during close
contact. People with suspected or confirmed COVID-19 should avoid
contact with animals.

What are antibodies and how do they help

protect me?
Antibodies are proteins your immune system makes to help fight infection and protect you from
getting sick in the future. A positive antibody test result can help identify someone who has had
COVID-19 in the past or has been vaccinated against COVID-19. Studies show that people who
have antibodies from an infection with the virus that causes COVID-19 can improve their level
of protection by getting vaccinated

What are ways to prevent COVID-19?

There are many actions you can take to help protect you, your
household, and your community from COVID-19. CDC’s COVID-19
hospital admission levels help individuals and communities decide
when to take action to protect yourself and others based on the latest
data and information from your area.

In addition to staying up to date with COVID-19 vaccines and basic

health and hygiene practices like handwashing, CDC recommends
some prevention actions at all COVID-19 hospital admission levels.
Who is at risk of severe illness from COVID-
19?
Some people are more likely than others to get very sick if they get
COVID-19. This includes people who are older,
are immunocompromised, have certain disabilities, or have underlying
health conditions. Understanding your COVID-19 risk and the risks that
might affect others can help you make decisions to protect yourself
and others.

What are variants of COVID-19?

Viruses are constantly changing, including the virus that causes
COVID-19. These changes occur over time and can lead to new strains
of the virus or variants of COVID-19 . Slowing the spread of the virus,
by protecting yourself and others, can help slow new variants from
developing. CDC is working with state and local public health officials
to monitor the spread of all variants, including Omicron.

How does the coronavirus spread?

As of now, researchers know that the coronavirus is spread through droplets and
virus particles released into the air when an infected person breathes, talks,
laughs, sings, coughs or sneezes. Larger droplets may fall to the ground in a few
seconds, but tiny infectious particles can linger in the air and accumulate in indoor
places, especially where many people are gathered and there is poor ventilation.
This is why mask-wearing, hand hygiene and physical distancing are essential to
preventing COVID-19.

How did the coronavirus start?

The first case of COVID-19 was reported Dec. 1, 2019, and the cause was a then-
new coronavirus later named SARS-CoV-2. SARS-CoV-2 may have originated in an
animal and changed (mutated) so it could cause illness in humans. In the past,
several infectious disease outbreaks have been traced to viruses originating in
birds, pigs, bats and other animals that mutated to become dangerous to humans.
Research continues, and more study may reveal how and why the coronavirus
evolved to cause pandemic disease.

What is the incubation period for COVID-19?

Symptoms show up in people within two to 14 days of exposure to the virus. A

person infected with the coronavirus is contagious to others for up to two days
before symptoms appear, and they remain contagious to others for 10 to 20 days,
depending upon their immune system and the severity of their illness.

Some people infected with the coronavirus have mild COVID-19 illness, and others
have no symptoms at all. In some cases, however, COVID-19 can lead to
respiratory failure, lasting lung and heart muscle damage, nervous system
problems, kidney failure or death.

If you have a fever or any of the symptoms listed above, call your doctor or a
health care provider and explain your symptoms over the phone before going to
the doctor’s office, urgent care facility or emergency room. Here are suggestions if
you feel sick and are concerned you might have COVID-19.

How is COVID-19 diagnosed?

COVID-19 is diagnosed through a test. Diagnosis by examination alone is difficult

since many COVID-19 signs and symptoms can be caused by other illnesses. Some
people with the coronavirus do not have symptoms at all. Learn more about
COVID-19 testing.

How is COVID-19 treated?

Treatment for COVID-19 depends on the severity of the infection. For milder
illness, resting at home and taking medicine to reduce fever is often sufficient.
More severe cases may require hospitalization, with treatment that might include
intravenous medications, supplemental oxygen, assisted ventilation and other
supportive measures

How do you protect yourself from this?

There are several COVID-19 vaccines recommended by the CDC. It is also

important to receive a booster when you are eligible.

In addition, it helps to keep up with other safety precautions, such as following

testing guidelines, wearing a mask, washing your hands and practicing physical
distancing.

Does COVID-19 cause death?

Yes, severe COVID-19 can be fatal. For updates of coronavirus infections, deaths
and vaccinations worldwide, see the Coronavirus COVID-19 Global Cases map
developed by the Johns Hopkins Center for Systems Science and Engineering.

Two COVID-19 vaccines – Pfizer and Moderna - have been fully approved by the
FDA and recommended by the CDC as highly effective in preventing serious
disease, hospitalization and death from COVID-19.

The CDC notes that in most situations the two mRNA vaccines from Pfizer and
Moderna are preferred over the Johnson & Johnson vaccine due to a risk of serious
adverse events.

It is also important to receive a booster when eligible. You can get any of these
three authorized or approved vaccines, but the CDC explains that Pfizer and
Moderna are preferred in most situations.

Why is it called coronavirus?

Coronaviruses are named for their appearance: “corona” means “crown.” The
virus’s outer layers are covered with spike proteins that surround them like a
crown.

Is this coronavirus different from SARS?

SARS stands for severe acute respiratory syndrome. In 2003, an outbreak of SARS
affected people in several countries before ending in 2004. The coronavirus that
causes COVID-19 is similar to the one that caused the 2003 SARS outbreak.

Since the 2019 coronavirus is related to the original coronavirus that caused SARS
and can also cause severe acute respiratory syndrome, there is “SARS” in its name:
SARS-CoV-2. Much is still unknown about these viruses, but SARS-CoV-2 spreads
faster and farther than the 2003 SARS-CoV-1 virus. This is likely because of how
easily it is transmitted person to person, even from asymptomatic carriers of the
virus.

Are there different variants of this coronavirus?

Yes, there are different variants of this coronavirus. Like other viruses, the
coronavirus that causes COVID-19 can change (mutate). Mutations may enable the
coronavirus to spread faster from person to person as in the case of the delta and
omicron variants. More infections can result in more people getting very sick and
also create more opportunity for the virus to develop further mutations. Read
more about coronavirus variants.

Coronaviruses are a family of viruses that can cause illnesses such as the common
cold, severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome
(MERS). In 2019, a new coronavirus was identified as the cause of a disease outbreak
that originated in China.
The virus is known as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).
The disease it causes is called coronavirus disease 2019 (COVID-19). In March 2020,
the World Health Organization (WHO) declared the COVID-19 outbreak a pandemic.
Public health groups, including the U.S. Centers for Disease Control and Prevention
(CDC) and WHO, are monitoring the COVID-19 pandemic and posting updates on their
websites. These groups have also issued recommendations for preventing and treating
the virus that causes COVID-19.

Symptoms
Signs and symptoms of coronavirus disease 2019 (COVID-19) may appear 2 to 14 days
after exposure. This time after exposure and before having symptoms is called the
incubation period. You can still spread COVID-19 before you have symptoms
(presymptomatic transmission). Common signs and symptoms can include:

 Fever
 Cough
  Tiredness
Early symptoms of COVID-19 may include a loss of taste or smell.
Other symptoms can include:

 Shortness of breath or difficulty breathing

 Muscle aches
 Chills
 Sore throat
 Runny nose
 Headache
 Chest pain
 Pink eye (conjunctivitis)
 Nausea
 Vomiting
 Diarrhea
 Rash
This list isn't complete. Children have similar symptoms to adults and generally have
mild illness.
The severity of COVID-19 symptoms can range from very mild to severe. Some people
may have only a few symptoms. Some people may have no symptoms at all, but can
still spread it (asymptomatic transmission). Some people may experience worsened
symptoms, such as worsened shortness of breath and pneumonia, about a week after
symptoms start.
Some people experience COVID-19symptoms for more than four weeks after they're
diagnosed. These health issues are sometimes called post-COVID-19 conditions. Some
children experience multisystem inflammatory syndrome, a syndrome that can affect
some organs and tissues, several weeks after having COVID-19. Rarely, some adults
experience the syndrome too.
People who are older have a higher risk of serious illness from COVID-19, and the risk
increases with age. People who have existing medical conditions also may have a
higher risk of serious illness. Certain medical conditions that may increase the risk of
serious illness from COVID-19 include:

 Serious heart diseases, such as heart failure, coronary artery disease or

cardiomyopathy
  Cancer
 Chronic obstructive pulmonary disease (COPD)
 Type 1 or type 2 diabetes
 Overweight, obesity or severe obesity
 High blood pressure
 Smoking
 Chronic kidney disease
 Sickle cell disease or thalassemia
 Weakened immune system from solid organ transplants or bone marrow
transplants
 Pregnancy
 Asthma
 Chronic lung diseases such as cystic fibrosis or pulmonary hypertension
 Liver disease
 Dementia
 Down syndrome
 Weakened immune system from bone marrow transplant, HIV or some
medications
 Brain and nervous system conditions, such as strokes
 Substance use disorders
This list is not complete. Other medical conditions may increase your risk of serious
illness from COVID-19.

When to see a doctor

If you have COVID-19 signs or symptoms or you've been in contact with someone
diagnosed with COVID-19, contact your health care provider right away for medical
advice. Your health care provider will likely recommend that you get tested for COVID-
19. If you have emergency COVID-19 symptoms, such as trouble breathing, seek care
immediately. If you need to go to a hospital, call ahead so that health care providers can
take steps to ensure that others aren't exposed.
If you have emergency COVID-19 signs and symptoms, seek care immediately.
Emergency signs and symptoms can include:

 Trouble breathing
 Persistent chest pain or pressure
 Inability to stay awake
 New confusion
 Pale, gray or blue-colored skin, lips or nail beds — depending on skin tone
This list isn't complete. Let your health care provider know if you are an older adult or
have chronic medical conditions, such as heart disease or lung disease, as you may
have a greater risk of becoming seriously ill with COVID-19

Causes
Infection with severe acute respiratory syndrome coronavirus 2, or SARS-CoV-2,
causes coronavirus disease 2019 (COVID-19).
The virus that causes COVID-19 spreads easily among people. Data has shown that
the COVID-19 virus spreads mainly from person to person among those in close
contact. The virus spreads by respiratory droplets released when someone with the
virus coughs, sneezes, breathes, sings or talks. These droplets can be inhaled or land
in the mouth, nose or eyes of a person nearby.
Sometimes the COVID-19 virus can spread when a person is exposed to very small
droplets or aerosols that stay in the air for several minutes or hours — called airborne
transmission.
The virus can also spread if you touch a surface with the virus on it and then touch your
mouth, nose or eyes. But the risk is low.
The COVID-19 virus can spread from someone who is infected but has no symptoms.
This is called asymptomatic transmission. The COVID-19 virus can also spread from
someone who is infected but hasn't developed symptoms yet. This is called
presymptomatic transmission.
It's possible to get COVID-19 more than once.

Risk factors
Risk factors for COVID-19 appear to include:

 Close contact with someone who has COVID-19, especially someone with
symptoms
  Being coughed or sneezed on by an infected person
 Being near an infected person when in an indoor space with poor air flow

Complications
Although most people with COVID-19 have mild to moderate symptoms, the disease
can cause severe medical complications and lead to death in some people. Older adults
or people with existing medical conditions are at greater risk of becoming seriously ill
with COVID-19.
Complications can include:

 Pneumonia and trouble breathing

 Organ failure in several organs
 Heart problems
 A severe lung condition that causes a low amount of oxygen to go through
your bloodstream to your organs (acute respiratory distress syndrome)
 Blood clots
 Acute kidney injury
 Additional viral and bacterial infections

The U.S. Food and Drug Administration (FDA) has given emergency use authorization
to some COVID-19 vaccines in the United States. The FDA has approved the Pfizer-
BioNTech COVID-19 vaccine, now called Comirnaty, to prevent COVID-19 in people
age 12 and older. The FDA has given emergency use authorization to Pfizer-
BioNTech COVID-19 vaccines for ages 6 months through 11.
The FDA has approved the Moderna vaccine, now called Spikevax, to prevent COVID-
19 in people age 18 and older. The FDA has also authorized the Moderna COVID-
19 vaccine in children ages 6 months through 17 years old. The FDA has also
authorized the Novavax COVID-19, adjuvanted vaccine to prevent COVID-19 in people
age 12 and older.
Due to the risk of a potentially life-threatening blood-clotting problem, the FDA is
restricting use of the Janssen/Johnson & Johnson vaccine to certain people age 18 and
older. Examples include people who had a severe allergic reaction after getting
an mRNACOVID-19 vaccine and people who can't get an mRNA COVID-19 vaccine
due to limited access or personal or religious concerns. If you get this vaccine, be sure
to understand the risks and symptoms of the blood-clotting problem.
A vaccine can prevent you from getting the COVID-19 virus or prevent you from
becoming seriously ill if you get the COVID-19virus. In addition, COVID-19 vaccination
might offer better protection than getting sick with COVID-19. A recent study showed
that unvaccinated people who already had COVID-19 are more than twice as likely as
fully vaccinated people to get reinfected with COVID-19.
After getting vaccinated, you can more safely return to many activities you may not have
been able to do because of the pandemic. However, if you are in an area with a high
number of people with COVID-19 in the hospital and new COVID-19 cases,
the CDCrecommends wearing a mask indoors in public. You're considered fully
vaccinated two weeks after you get a second dose of an mRNA COVID-19 vaccine,
after two doses of the Novavax vaccine, or two weeks after you get a single dose of the
Janssen/Johnson & Johnson COVID-19 vaccine. You are considered up to date with
your vaccines if you have gotten all recommended COVID-19vaccines, including
booster doses, when you become eligible.
An additional primary dose of a COVID-19vaccine is recommended for people who are
vaccinated and might not have had a strong enough immune response.
In contrast, a booster dose is recommended for people who are vaccinated and whose
immune response weakened over time. Research suggests that getting a booster dose
can decrease your risk of infection and severe illness with COVID-19.
People who have a moderately or severely weakened immune system should get an
additional primary shot and a booster shot.
The CDC recommends additional doses and booster doses of COVID-19 vaccines in
specific instances:
 Additional primary shot. The CDCrecommends an additional primary shot
of an mRNA COVID-19 vaccine for some people with weakened immune
systems, such as those who have had an organ transplant. People with
weakened immune systems might not develop enough immunity after
vaccination with two doses of an mRNA COVID-19 vaccine or one dose of
the Janssen/Johnson & Johnson COVID-19 vaccine. An additional shot
using an mRNA COVID-19 vaccine might improve their protection
against COVID-19. This recommendation for an additional mRNA COVID-
19 shot is for people ages 6 months and older.
The additional primary shot should be given at least four weeks after a
second dose of an mRNA COVID-19 vaccine or one dose of the
Janssen/Johnson & Johnson COVID-19 vaccine. The additional primary
shot should be the same brand as the other two mRNACOVID-19 vaccine
doses that were given. If the brand given isn't known, either brand
of mRNA COVID-19 vaccine can be given as a third dose.
 Booster dose. These recommendations differ by age, what vaccines you
have been given and the state of your immune system. But in general,
people can get the booster shot at least two months after their last shot.
 People who recently had a positive COVID-19 test may think about waiting
three months after their symptoms started to get the booster.
Kids ages 6 months through 4 years who got the Moderna COVID-
19 vaccine can only get an updated, called bivalent, Moderna COVID-
19 vaccine booster. The booster is based on the original virus strain and two
omicron strains.
Kids age 6 months through 5 years who got the Pfizer-BioNTech COVID-
19vaccine can only get the updated Pfizer-BioNTech booster. The booster
is based on the original virus strain and two omicron strains.
People age 5 and older who got the Moderna COVID-19 vaccine, and
people age 6 and older who got either vaccine can choose between the
updated Pfizer-BioNTech and the updated Moderna COVID-19 bivalent
vaccine boosters.
People age 12 and older who got the Novavax COVID-19 vaccine can
choose between the updated Pfizer-BioNTech and the updated
Moderna COVID-19bivalent vaccine boosters.
If you are age 18 or older, and got the Janssen COVID-19 vaccine, you can
get either of the mRNA vaccine bivalent boosters at least two months after
your shot. People 18 and older may also get a Novavax booster based on
the original virus strain as a first booster at least six months after their last
shot.
Pregnant people can also get a COVID-19booster dose.
There are many steps you can take to reduce your risk of infection from the COVID-
19 virus and reduce the risk of spreading it to others. WHO and CDC recommend
following these precautions:

 Get vaccinated. COVID-19 vaccines reduce the risk of getting and

spreading COVID-19.
 Avoid close contact with anyone who is sick or has symptoms.
 Keep distance between yourself and others when you're in indoor public
spaces. This is especially important if you have a higher risk of serious
illness. Keep in mind some people may have COVID-19and spread it to
others, even if they don't have symptoms or don't know they have COVID-
19.
 Avoid crowds and indoor places that have poor air flow (ventilation).
 Wash your hands often with soap and water for at least 20 seconds, or use
an alcohol-based hand sanitizer that contains at least 60% alcohol.
 Wear a face mask in indoor public spaces if you're in an area with a high
number of people with COVID-19 in the hospital and new COVID-19 cases,
 whether or not you're vaccinated. The CDC recommends wearing the most
protective mask possible that you'll wear regularly, fits well and is
comfortable.
 Improve the air flow indoors. Open windows. Turn on fans to direct air out of
windows. If you can't open windows, consider using air filters. And turn on
exhaust fans in your bathroom and kitchen. You might also consider a
portable air cleaner.
 Cover your mouth and nose with your elbow or a tissue when you cough or
sneeze. Throw away the used tissue. Wash your hands right away.
 Avoid touching your eyes, nose and mouth.
 Avoid sharing dishes, glasses, towels, bedding and other household items if
you're sick.
 Clean and disinfect high-touch surfaces, such as doorknobs, light switches,
electronics and counters, regularly.
 Stay home from work, school and public areas and stay home in isolation if
you're sick, unless you're going to get medical care. Avoid public
transportation, taxis and ride-hailing services if you're sick.
If you have a chronic medical condition and may have a higher risk of serious illness,
check with your doctor about other ways to protect yourself.

COVID-19 spreads when an infected person breathes out droplets and

very small particles that contain the virus. Other people can breathe in
these droplets and particles, or these droplets and particles can land
on their eyes, nose, or mouth. In some circumstances, these droplets
may contaminate surfaces they touch.

Anyone infected with COVID-19 can spread it, even if they do NOT
have symptoms.

The risk of animals spreading the virus that causes COVID-19 to people
is low. The virus can spread from people to animals during close
contact. People with suspected or confirmed COVID-19 should avoid
contact with animals.

What are antibodies and how do they help

protect me?
Antibodies are proteins your immune system makes to help fight infection and protect you from
getting sick in the future. A positive antibody test result can help identify someone who has had
COVID-19 in the past or has been vaccinated against COVID-19. Studies show that people who
have antibodies from an infection with the virus that causes COVID-19 can improve their level
of protection by getting vaccinated

What are ways to prevent COVID-19?

There are many actions you can take to help protect you, your
household, and your community from COVID-19. CDC’s COVID-19
hospital admission levels help individuals and communities decide
when to take action to protect yourself and others based on the latest
data and information from your area.

In addition to staying up to date with COVID-19 vaccines and basic

health and hygiene practices like handwashing, CDC recommends
some prevention actions at all COVID-19 hospital admission levels.

Who is at risk of severe illness from COVID-

19?
Some people are more likely than others to get very sick if they get
COVID-19. This includes people who are older,
are immunocompromised, have certain disabilities, or have underlying
health conditions. Understanding your COVID-19 risk and the risks that
might affect others can help you make decisions to protect yourself
and others.

What are variants of COVID-19?

Viruses are constantly changing, including the virus that causes
COVID-19. These changes occur over time and can lead to new strains
of the virus or variants of COVID-19 . Slowing the spread of the virus,
by protecting yourself and others, can help slow new variants from
developing. CDC is working with state and local public health officials
to monitor the spread of all variants, including Omicron.

How does the coronavirus spread?

As of now, researchers know that the coronavirus is spread through droplets and
virus particles released into the air when an infected person breathes, talks,
laughs, sings, coughs or sneezes. Larger droplets may fall to the ground in a few
seconds, but tiny infectious particles can linger in the air and accumulate in indoor
places, especially where many people are gathered and there is poor ventilation.
This is why mask-wearing, hand hygiene and physical distancing are essential to
preventing COVID-19.

How did the coronavirus start?

The first case of COVID-19 was reported Dec. 1, 2019, and the cause was a then-
new coronavirus later named SARS-CoV-2. SARS-CoV-2 may have originated in an
animal and changed (mutated) so it could cause illness in humans. In the past,
several infectious disease outbreaks have been traced to viruses originating in
birds, pigs, bats and other animals that mutated to become dangerous to humans.
Research continues, and more study may reveal how and why the coronavirus
evolved to cause pandemic disease.

What is the incubation period for COVID-19?

Symptoms show up in people within two to 14 days of exposure to the virus. A
person infected with the coronavirus is contagious to others for up to two days
before symptoms appear, and they remain contagious to others for 10 to 20 days,
depending upon their immune system and the severity of their illness.

Some people infected with the coronavirus have mild COVID-19 illness, and others
have no symptoms at all. In some cases, however, COVID-19 can lead to
respiratory failure, lasting lung and heart muscle damage, nervous system
problems, kidney failure or death.

If you have a fever or any of the symptoms listed above, call your doctor or a
health care provider and explain your symptoms over the phone before going to
the doctor’s office, urgent care facility or emergency room. Here are suggestions if
you feel sick and are concerned you might have COVID-19.

How is COVID-19 diagnosed?

COVID-19 is diagnosed through a test. Diagnosis by examination alone is difficult

since many COVID-19 signs and symptoms can be caused by other illnesses. Some
people with the coronavirus do not have symptoms at all. Learn more about
COVID-19 testing.

How is COVID-19 treated?

Treatment for COVID-19 depends on the severity of the infection. For milder
illness, resting at home and taking medicine to reduce fever is often sufficient.
More severe cases may require hospitalization, with treatment that might include
intravenous medications, supplemental oxygen, assisted ventilation and other
supportive measures
How do you protect yourself from this?

There are several COVID-19 vaccines recommended by the CDC. It is also

important to receive a booster when you are eligible.

In addition, it helps to keep up with other safety precautions, such as following

testing guidelines, wearing a mask, washing your hands and practicing physical
distancing.

Does COVID-19 cause death?

Yes, severe COVID-19 can be fatal. For updates of coronavirus infections, deaths
and vaccinations worldwide, see the Coronavirus COVID-19 Global Cases map
developed by the Johns Hopkins Center for Systems Science and Engineering.

Two COVID-19 vaccines – Pfizer and Moderna - have been fully approved by the
FDA and recommended by the CDC as highly effective in preventing serious
disease, hospitalization and death from COVID-19.

The CDC notes that in most situations the two mRNA vaccines from Pfizer and
Moderna are preferred over the Johnson & Johnson vaccine due to a risk of serious
adverse events.

It is also important to receive a booster when eligible. You can get any of these
three authorized or approved vaccines, but the CDC explains that Pfizer and
Moderna are preferred in most situations.

Why is it called coronavirus?

Coronaviruses are named for their appearance: “corona” means “crown.” The
virus’s outer layers are covered with spike proteins that surround them like a
crown.
Is this coronavirus different from SARS?

SARS stands for severe acute respiratory syndrome. In 2003, an outbreak of SARS
affected people in several countries before ending in 2004. The coronavirus that
causes COVID-19 is similar to the one that caused the 2003 SARS outbreak.

Since the 2019 coronavirus is related to the original coronavirus that caused SARS
and can also cause severe acute respiratory syndrome, there is “SARS” in its name:
SARS-CoV-2. Much is still unknown about these viruses, but SARS-CoV-2 spreads
faster and farther than the 2003 SARS-CoV-1 virus. This is likely because of how
easily it is transmitted person to person, even from asymptomatic carriers of the
virus.

Are there different variants of this coronavirus?

Yes, there are different variants of this coronavirus. Like other viruses, the
coronavirus that causes COVID-19 can change (mutate). Mutations may enable the
coronavirus to spread faster from person to person as in the case of the delta and
omicron variants. More infections can result in more people getting very sick and
also create more opportunity for the virus to develop further mutations. Read
more about coronavirus variants.

Coronaviruses are a family of viruses that can cause illnesses such as the common
cold, severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome
(MERS). In 2019, a new coronavirus was identified as the cause of a disease outbreak
that originated in China.
The virus is known as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).
The disease it causes is called coronavirus disease 2019 (COVID-19). In March 2020,
the World Health Organization (WHO) declared the COVID-19 outbreak a pandemic.
Public health groups, including the U.S. Centers for Disease Control and Prevention
(CDC) and WHO, are monitoring the COVID-19 pandemic and posting updates on their
websites. These groups have also issued recommendations for preventing and treating
the virus that causes COVID-19.
Symptoms
Signs and symptoms of coronavirus disease 2019 (COVID-19) may appear 2 to 14 days
after exposure. This time after exposure and before having symptoms is called the
incubation period. You can still spread COVID-19 before you have symptoms
(presymptomatic transmission). Common signs and symptoms can include:

 Fever
 Cough
 Tiredness
Early symptoms of COVID-19 may include a loss of taste or smell.
Other symptoms can include:

 Shortness of breath or difficulty breathing

 Muscle aches
 Chills
 Sore throat
 Runny nose
 Headache
 Chest pain
 Pink eye (conjunctivitis)
 Nausea
 Vomiting
 Diarrhea
 Rash
This list isn't complete. Children have similar symptoms to adults and generally have
mild illness.
The severity of COVID-19 symptoms can range from very mild to severe. Some people
may have only a few symptoms. Some people may have no symptoms at all, but can
still spread it (asymptomatic transmission). Some people may experience worsened
symptoms, such as worsened shortness of breath and pneumonia, about a week after
symptoms start.
Some people experience COVID-19symptoms for more than four weeks after they're
diagnosed. These health issues are sometimes called post-COVID-19 conditions. Some
children experience multisystem inflammatory syndrome, a syndrome that can affect
some organs and tissues, several weeks after having COVID-19. Rarely, some adults
experience the syndrome too.
People who are older have a higher risk of serious illness from COVID-19, and the risk
increases with age. People who have existing medical conditions also may have a
higher risk of serious illness. Certain medical conditions that may increase the risk of
serious illness from COVID-19 include:

 Serious heart diseases, such as heart failure, coronary artery disease or

cardiomyopathy
 Cancer
 Chronic obstructive pulmonary disease (COPD)
 Type 1 or type 2 diabetes
 Overweight, obesity or severe obesity
 High blood pressure
 Smoking
 Chronic kidney disease
 Sickle cell disease or thalassemia
 Weakened immune system from solid organ transplants or bone marrow
transplants
 Pregnancy
 Asthma
 Chronic lung diseases such as cystic fibrosis or pulmonary hypertension
 Liver disease
 Dementia
 Down syndrome
 Weakened immune system from bone marrow transplant, HIV or some
medications
 Brain and nervous system conditions, such as strokes
 Substance use disorders
This list is not complete. Other medical conditions may increase your risk of serious
illness from COVID-19.

When to see a doctor

If you have COVID-19 signs or symptoms or you've been in contact with someone
diagnosed with COVID-19, contact your health care provider right away for medical
advice. Your health care provider will likely recommend that you get tested for COVID-
19. If you have emergency COVID-19 symptoms, such as trouble breathing, seek care
immediately. If you need to go to a hospital, call ahead so that health care providers can
take steps to ensure that others aren't exposed.
If you have emergency COVID-19 signs and symptoms, seek care immediately.
Emergency signs and symptoms can include:

 Trouble breathing
 Persistent chest pain or pressure
 Inability to stay awake
 New confusion
 Pale, gray or blue-colored skin, lips or nail beds — depending on skin tone
This list isn't complete. Let your health care provider know if you are an older adult or
have chronic medical conditions, such as heart disease or lung disease, as you may
have a greater risk of becoming seriously ill with COVID-19

Causes
Infection with severe acute respiratory syndrome coronavirus 2, or SARS-CoV-2,
causes coronavirus disease 2019 (COVID-19).
The virus that causes COVID-19 spreads easily among people. Data has shown that
the COVID-19 virus spreads mainly from person to person among those in close
contact. The virus spreads by respiratory droplets released when someone with the
virus coughs, sneezes, breathes, sings or talks. These droplets can be inhaled or land
in the mouth, nose or eyes of a person nearby.
Sometimes the COVID-19 virus can spread when a person is exposed to very small
droplets or aerosols that stay in the air for several minutes or hours — called airborne
transmission.
The virus can also spread if you touch a surface with the virus on it and then touch your
mouth, nose or eyes. But the risk is low.
The COVID-19 virus can spread from someone who is infected but has no symptoms.
This is called asymptomatic transmission. The COVID-19 virus can also spread from
someone who is infected but hasn't developed symptoms yet. This is called
presymptomatic transmission.
It's possible to get COVID-19 more than once.

Risk factors
Risk factors for COVID-19 appear to include:

 Close contact with someone who has COVID-19, especially someone with
symptoms
 Being coughed or sneezed on by an infected person
 Being near an infected person when in an indoor space with poor air flow

Complications
Although most people with COVID-19 have mild to moderate symptoms, the disease
can cause severe medical complications and lead to death in some people. Older adults
or people with existing medical conditions are at greater risk of becoming seriously ill
with COVID-19.
Complications can include:

 Pneumonia and trouble breathing

 Organ failure in several organs
 Heart problems
 A severe lung condition that causes a low amount of oxygen to go through
your bloodstream to your organs (acute respiratory distress syndrome)
 Blood clots
 Acute kidney injury
 Additional viral and bacterial infections

The U.S. Food and Drug Administration (FDA) has given emergency use authorization
to some COVID-19 vaccines in the United States. The FDA has approved the Pfizer-
BioNTech COVID-19 vaccine, now called Comirnaty, to prevent COVID-19 in people
age 12 and older. The FDA has given emergency use authorization to Pfizer-
BioNTech COVID-19 vaccines for ages 6 months through 11.
The FDA has approved the Moderna vaccine, now called Spikevax, to prevent COVID-
19 in people age 18 and older. The FDA has also authorized the Moderna COVID-
19 vaccine in children ages 6 months through 17 years old. The FDA has also
authorized the Novavax COVID-19, adjuvanted vaccine to prevent COVID-19 in people
age 12 and older.
Due to the risk of a potentially life-threatening blood-clotting problem, the FDA is
restricting use of the Janssen/Johnson & Johnson vaccine to certain people age 18 and
older. Examples include people who had a severe allergic reaction after getting
an mRNACOVID-19 vaccine and people who can't get an mRNA COVID-19 vaccine
due to limited access or personal or religious concerns. If you get this vaccine, be sure
to understand the risks and symptoms of the blood-clotting problem.
A vaccine can prevent you from getting the COVID-19 virus or prevent you from
becoming seriously ill if you get the COVID-19virus. In addition, COVID-19 vaccination
might offer better protection than getting sick with COVID-19. A recent study showed
that unvaccinated people who already had COVID-19 are more than twice as likely as
fully vaccinated people to get reinfected with COVID-19.
After getting vaccinated, you can more safely return to many activities you may not have
been able to do because of the pandemic. However, if you are in an area with a high
number of people with COVID-19 in the hospital and new COVID-19 cases,
the CDCrecommends wearing a mask indoors in public. You're considered fully
vaccinated two weeks after you get a second dose of an mRNA COVID-19 vaccine,
after two doses of the Novavax vaccine, or two weeks after you get a single dose of the
Janssen/Johnson & Johnson COVID-19 vaccine. You are considered up to date with
your vaccines if you have gotten all recommended COVID-19vaccines, including
booster doses, when you become eligible.
An additional primary dose of a COVID-19vaccine is recommended for people who are
vaccinated and might not have had a strong enough immune response.
In contrast, a booster dose is recommended for people who are vaccinated and whose
immune response weakened over time. Research suggests that getting a booster dose
can decrease your risk of infection and severe illness with COVID-19.
People who have a moderately or severely weakened immune system should get an
additional primary shot and a booster shot.
The CDC recommends additional doses and booster doses of COVID-19 vaccines in
specific instances:
 Additional primary shot. The CDCrecommends an additional primary shot
of an mRNA COVID-19 vaccine for some people with weakened immune
systems, such as those who have had an organ transplant. People with
weakened immune systems might not develop enough immunity after
vaccination with two doses of an mRNA COVID-19 vaccine or one dose of
 the Janssen/Johnson & Johnson COVID-19 vaccine. An additional shot
using an mRNA COVID-19 vaccine might improve their protection
against COVID-19. This recommendation for an additional mRNA COVID-
19 shot is for people ages 6 months and older.
The additional primary shot should be given at least four weeks after a
second dose of an mRNA COVID-19 vaccine or one dose of the
Janssen/Johnson & Johnson COVID-19 vaccine. The additional primary
shot should be the same brand as the other two mRNACOVID-19 vaccine
doses that were given. If the brand given isn't known, either brand
of mRNA COVID-19 vaccine can be given as a third dose.
 Booster dose. These recommendations differ by age, what vaccines you
have been given and the state of your immune system. But in general,
people can get the booster shot at least two months after their last shot.
People who recently had a positive COVID-19 test may think about waiting
three months after their symptoms started to get the booster.
Kids ages 6 months through 4 years who got the Moderna COVID-
19 vaccine can only get an updated, called bivalent, Moderna COVID-
19 vaccine booster. The booster is based on the original virus strain and two
omicron strains.
Kids age 6 months through 5 years who got the Pfizer-BioNTech COVID-
19vaccine can only get the updated Pfizer-BioNTech booster. The booster
is based on the original virus strain and two omicron strains.
People age 5 and older who got the Moderna COVID-19 vaccine, and
people age 6 and older who got either vaccine can choose between the
updated Pfizer-BioNTech and the updated Moderna COVID-19 bivalent
vaccine boosters.
People age 12 and older who got the Novavax COVID-19 vaccine can
choose between the updated Pfizer-BioNTech and the updated
Moderna COVID-19bivalent vaccine boosters.
If you are age 18 or older, and got the Janssen COVID-19 vaccine, you can
get either of the mRNA vaccine bivalent boosters at least two months after
your shot. People 18 and older may also get a Novavax booster based on
the original virus strain as a first booster at least six months after their last
shot.
Pregnant people can also get a COVID-19booster dose.
There are many steps you can take to reduce your risk of infection from the COVID-
19 virus and reduce the risk of spreading it to others. WHO and CDC recommend
following these precautions:

 Get vaccinated. COVID-19 vaccines reduce the risk of getting and

spreading COVID-19.
  Avoid close contact with anyone who is sick or has symptoms.
 Keep distance between yourself and others when you're in indoor public
spaces. This is especially important if you have a higher risk of serious
illness. Keep in mind some people may have COVID-19and spread it to
others, even if they don't have symptoms or don't know they have COVID-
19.
 Avoid crowds and indoor places that have poor air flow (ventilation).
 Wash your hands often with soap and water for at least 20 seconds, or use
an alcohol-based hand sanitizer that contains at least 60% alcohol.
 Wear a face mask in indoor public spaces if you're in an area with a high
number of people with COVID-19 in the hospital and new COVID-19 cases,
whether or not you're vaccinated. The CDC recommends wearing the most
protective mask possible that you'll wear regularly, fits well and is
comfortable.
 Improve the air flow indoors. Open windows. Turn on fans to direct air out of
windows. If you can't open windows, consider using air filters. And turn on
exhaust fans in your bathroom and kitchen. You might also consider a
portable air cleaner.
 Cover your mouth and nose with your elbow or a tissue when you cough or
sneeze. Throw away the used tissue. Wash your hands right away.
 Avoid touching your eyes, nose and mouth.
 Avoid sharing dishes, glasses, towels, bedding and other household items if
you're sick.
 Clean and disinfect high-touch surfaces, such as doorknobs, light switches,
electronics and counters, regularly.
 Stay home from work, school and public areas and stay home in isolation if
you're sick, unless you're going to get medical care. Avoid public
transportation, taxis and ride-hailing services if you're sick.
If you have a chronic medical condition and may have a higher risk of serious illness,
check with your doctor about other ways to protect yourself.

COVID-19 spreads when an infected person breathes out droplets and

very small particles that contain the virus. Other people can breathe in
these droplets and particles, or these droplets and particles can land
on their eyes, nose, or mouth. In some circumstances, these droplets
may contaminate surfaces they touch.
Anyone infected with COVID-19 can spread it, even if they do NOT
have symptoms.

The risk of animals spreading the virus that causes COVID-19 to people
is low. The virus can spread from people to animals during close
contact. People with suspected or confirmed COVID-19 should avoid
contact with animals.

What are antibodies and how do they help

protect me?
Antibodies are proteins your immune system makes to help fight infection and protect you from
getting sick in the future. A positive antibody test result can help identify someone who has had
COVID-19 in the past or has been vaccinated against COVID-19. Studies show that people who
have antibodies from an infection with the virus that causes COVID-19 can improve their level
of protection by getting vaccinated

What are ways to prevent COVID-19?

There are many actions you can take to help protect you, your
household, and your community from COVID-19. CDC’s COVID-19
hospital admission levels help individuals and communities decide
when to take action to protect yourself and others based on the latest
data and information from your area.

In addition to staying up to date with COVID-19 vaccines and basic

health and hygiene practices like handwashing, CDC recommends
some prevention actions at all COVID-19 hospital admission levels.

Who is at risk of severe illness from COVID-

19?
Some people are more likely than others to get very sick if they get
COVID-19. This includes people who are older,
are immunocompromised, have certain disabilities, or have underlying
health conditions. Understanding your COVID-19 risk and the risks that
might affect others can help you make decisions to protect yourself
and others.

What are variants of COVID-19?

Viruses are constantly changing, including the virus that causes
COVID-19. These changes occur over time and can lead to new strains
of the virus or variants of COVID-19 . Slowing the spread of the virus,
by protecting yourself and others, can help slow new variants from
developing. CDC is working with state and local public health officials
to monitor the spread of all variants, including Omicron.

How does the coronavirus spread?

As of now, researchers know that the coronavirus is spread through droplets and
virus particles released into the air when an infected person breathes, talks,
laughs, sings, coughs or sneezes. Larger droplets may fall to the ground in a few
seconds, but tiny infectious particles can linger in the air and accumulate in indoor
places, especially where many people are gathered and there is poor ventilation.
This is why mask-wearing, hand hygiene and physical distancing are essential to
preventing COVID-19.

How did the coronavirus start?

The first case of COVID-19 was reported Dec. 1, 2019, and the cause was a then-
new coronavirus later named SARS-CoV-2. SARS-CoV-2 may have originated in an
animal and changed (mutated) so it could cause illness in humans. In the past,
several infectious disease outbreaks have been traced to viruses originating in
birds, pigs, bats and other animals that mutated to become dangerous to humans.
Research continues, and more study may reveal how and why the coronavirus
evolved to cause pandemic disease.

What is the incubation period for COVID-19?

Symptoms show up in people within two to 14 days of exposure to the virus. A

person infected with the coronavirus is contagious to others for up to two days
before symptoms appear, and they remain contagious to others for 10 to 20 days,
depending upon their immune system and the severity of their illness.

Some people infected with the coronavirus have mild COVID-19 illness, and others
have no symptoms at all. In some cases, however, COVID-19 can lead to
respiratory failure, lasting lung and heart muscle damage, nervous system
problems, kidney failure or death.

If you have a fever or any of the symptoms listed above, call your doctor or a
health care provider and explain your symptoms over the phone before going to
the doctor’s office, urgent care facility or emergency room. Here are suggestions if
you feel sick and are concerned you might have COVID-19.

How is COVID-19 diagnosed?

COVID-19 is diagnosed through a test. Diagnosis by examination alone is difficult

since many COVID-19 signs and symptoms can be caused by other illnesses. Some
people with the coronavirus do not have symptoms at all. Learn more about
COVID-19 testing.

How is COVID-19 treated?

Treatment for COVID-19 depends on the severity of the infection. For milder
illness, resting at home and taking medicine to reduce fever is often sufficient.
More severe cases may require hospitalization, with treatment that might include
intravenous medications, supplemental oxygen, assisted ventilation and other
supportive measures

How do you protect yourself from this?

There are several COVID-19 vaccines recommended by the CDC. It is also

important to receive a booster when you are eligible.

In addition, it helps to keep up with other safety precautions, such as following

testing guidelines, wearing a mask, washing your hands and practicing physical
distancing.

Does COVID-19 cause death?

Yes, severe COVID-19 can be fatal. For updates of coronavirus infections, deaths
and vaccinations worldwide, see the Coronavirus COVID-19 Global Cases map
developed by the Johns Hopkins Center for Systems Science and Engineering.

Two COVID-19 vaccines – Pfizer and Moderna - have been fully approved by the
FDA and recommended by the CDC as highly effective in preventing serious
disease, hospitalization and death from COVID-19.

The CDC notes that in most situations the two mRNA vaccines from Pfizer and
Moderna are preferred over the Johnson & Johnson vaccine due to a risk of serious
adverse events.
It is also important to receive a booster when eligible. You can get any of these
three authorized or approved vaccines, but the CDC explains that Pfizer and
Moderna are preferred in most situations.

Why is it called coronavirus?

Coronaviruses are named for their appearance: “corona” means “crown.” The
virus’s outer layers are covered with spike proteins that surround them like a
crown.

Is this coronavirus different from SARS?

SARS stands for severe acute respiratory syndrome. In 2003, an outbreak of SARS
affected people in several countries before ending in 2004. The coronavirus that
causes COVID-19 is similar to the one that caused the 2003 SARS outbreak.

Since the 2019 coronavirus is related to the original coronavirus that caused SARS
and can also cause severe acute respiratory syndrome, there is “SARS” in its name:
SARS-CoV-2. Much is still unknown about these viruses, but SARS-CoV-2 spreads
faster and farther than the 2003 SARS-CoV-1 virus. This is likely because of how
easily it is transmitted person to person, even from asymptomatic carriers of the
virus.

Are there different variants of this coronavirus?

Yes, there are different variants of this coronavirus. Like other viruses, the
coronavirus that causes COVID-19 can change (mutate). Mutations may enable the
coronavirus to spread faster from person to person as in the case of the delta and
omicron variants. More infections can result in more people getting very sick and
also create more opportunity for the virus to develop further mutations. Read
more about coronavirus variants.
Category A agents (cholera,
plague). Patients should be placed
in separate rooms or cohorted
together. Negative pressure rooms
are not generally needed. The
rooms and surfaces and equipment
should undergo regular
decontamination preferably with
sodium hypochlorite. Healthcare
workers should be provided withfit
tested 95 respirators and protective
suits and goggles. Airborne
transmission precautions should be
taken during aerosol generating
procedures such as intubation,
suction
and tracheostomies. A contacts
including healthcare workers
should
 be monitored for development of
symptoms of COVID-19. Patients
can be discharged from isolation
once they are afebrile for atleast 3d
and have two consecutive negative
molecular tests at 1 d sampling
interval. This recommendation is
different from
pandemic flu where patients were
considerable protection in mice
against a MERS- CoV lethal
challenge. Such antibodies may
play a crucial role in enhancing
protective humoral responses
against the emerging Cos by
aiming
appropriate epitopes and functions
of the S protein. The cross-
neutralization ability of SARS-
CoV BD- specific neutralizing
MAbs considerably relies on the
resemblance between their RBDs;
therefore, SARS-CoV RBD-
specific antibodies could cross-
neutralized SL CoVs, i.e., bat-SL-
CoV strain WIVI (RBD with eight
amino acid differences from
SARS- Co) but not bat-SL-CoV
strain SHC014 (24 amino
acid differences) (200).
Appropriate RBD-specific MAbs
can be recognized by a relative
analvsis of RBD of SARS- CoV-2
to that of SARS-CoV, and cross-
neutralizing SARS-CoV RBD-
specific MAbs could be explored
for their effectiveness against
COVID-19 and further need to be
assessed clinically. The U.S.
biotechnology company
Regeneron is attempting to
recognize potent and specific
MAbs to combat COVID-19. An
ideal therapeutic option suggested
for SARS-CoV-2 (COVID-19) is
the combination therapy comprised
of MAbs and the drug remdesivir
(COVID-19) (201). The SARS-
CoV-specific human MAb
CR3022 is found to bind with
SARS-CoV-2
RBD, indicating its potential as a
therapeutic agent other clinical
trials in different phases are still
ongoing elsewhere.

Immunomodulatory agents. SARS-

CoV-2 triggers a strong immune
response which may cause
cytokine storm syndrome*. Thus,
immunomodulatory agents that
inhibit the excessive inflammatory
response may
be a potential adjunctive therapy
for COVID- 19. Dexamethasone is
a corticosteroid often used in a
wide range of conditions to relieve
inflammation through
its anti-inflammatory and
immunosuppressant effects.
Recently, the RECOVERY trial
found dexamethasone reduced
mortality by about one third in
hospitalized patients with COVID-
19 who received invasive mechan-
ical ventilation and by one fifth in
patients receiving oxygen. By
contrast, no benefit was found in
patients
without respiratory support'*.
Tocilizumab and sarilumab, two
types of interleukin-6 (IL.-6)
receptor-specific antibodies
previously used to treat various
types of arthritis, including
rheumatoid arthritis, and cytokine
release syndrome, showed effec-
tiveness in the treatment of severe
COVID- 19 by atten- uating the
cytokine storm in a small
uncontrolled trial 7, Bevacizumab
is an anti-vascular endothelial
growth factor (VEGI) medication
that could potentially reduce
pulmonary edema in patients with
severe COVID-19. Eculizumab is
a specific monoclonal antibody
that
inhibits the proinflammatory
complement protein C5.
Preliminary results showed that it
induced a drop of inflammatory
markers and C-reactive protein
levels, suggesting its potential to
be an option for the treatment of
severe COVID- 19 (REF. 149.

Been used based on the experience

with SARS and MERS. In a
historical control study in patients
with SARS, patients treated with
lopinavir- ritonavir with ribavirin
had better outcomes as compared
to those given
ribavirin alone [151. In the case
series of 99 hospitalized patients
with COVID-19 infection from
Wuhan, oxygen was given to 76%,
non-
invasive ventilation in 13%.
mechanical ventilation in 4%,
extracorporeal membrane
oxygenation
(ECMO) in 3%. continuous renal
replacement therapy (CRRT) in
9%, antibiotics in 71%, antifungals
in 15%, glucocorticoids in 19%
and intravenous
immunoglobulin therapy in 27%
[15]. Antiviral therapy consisting
of oseltamivir, ganciclovir and
lopinavir- ritonavir was given to
75% of the patients. The duration
of non-invasive
ventilation was 4-22 d (median 9
dj).
Cases of COVID-19 in countries
outside China were reported in
those with no history of travel to
China suggesting that local
human-to- human transmission
was occurring in these countries
{9]. Airports in different countries
including India put in screening
mechanisms to detect symptomatic
people returning from China and
placed them in isolation and
testing them for COVID-19. Soon
it was apparent that the infection
could be transmitted from
asymptomatic people
and also before onset of
symptoms. Therefore, countries
including India who evacuated
their citizens from Wuhan through
special flights or had travellers
returning from China, placed all
people symptomatic or otherwise
in
isolation for 14d and tested them
for the virus.

Guo Yanhong, an official with the

National Health Commission
(NHC), stated that convalescent
plasma therapy is a significant
method for treating severe
COVID-19 patients. Among the
COVID-19 patients currently
receiving convalescent plasma
therapy in the virus-hit Wuhan,
one has been discharged from
hospital, as reported by Chinese
science authorities on Monday,
17th February 2020 in Beijing.
The first dose of convalescent
plasma from a COVID-19 patient
was collected on 1st and 9th
February 2020 from a severely ill
patient who was given treatment at
a hospital in Jiangxia District in
Wuhan. The presence of the virus
in patients is minimised by the
antibodies in the convalescent
plasma. Guigiang stated that
donating plasma may cause
minimal harm to the donor and
that there is nothing to be worried
about. Plasma donors must be
cured patients and discharged from
hospital. Only plasma is used,
whereas red blood cells (RBC),
white blood cells (WBC) and
blood platelets are transfused back
into the donor's body. Wang
alleged that donor's plasma will
totally improve to its initial state
after one or 2 weeks from the
day of plasma donation of around
200 to 300 millilitres.
Prevention [21, 30]
Sinco at this time mere are no
approved treatments for this
infection,
prevention is crucial. several
properties of this virus make
prevention difficult namely, non-
specific features of the disease, the
infectivity even before onset of
symptoms in the incubation period,
transmission from asymptomatic
people, long incubation period,
tropism
for mucosal surfaces such as the
conjunctiva, prolonged duration of
the
 illness and transmission even after
clinical recovery. Isolation of
confirmed or suspected
cases with mild illness at home is
recommender The ventilation at
home should be good with sunlight
to allow for destruction of virus.
Patients should be asked to wear a
simple surgical
mask and practice cough hygiene.

prongs, face mask, high flow nasal

cannula (HFNC) or non-invasive
ventilation is indicated. Mechanical
ventilation and even extra corporeal
membrane oxygen support may be
needed. Renal replacement therapy may
be needed in some. Antibiotics
and antitungals are required it co
infections are suspected or proven. The
role of corticosteroids is unproven; while
current international consensus and
WHO advocate against their use, Chinese
guidelines do recommend short term
therapy with low-to- moderate dose
corticosteroids in COVID-19 ARDS (24,
25]. Detailed guidelines for critical care
management for COVID-19 have been
published by the WHO [26]. There is, as
of now, no approved treatment for
COVID-19. Antiviral drugs such as
ribavirin, lopinavir-ritonavir have been
used based on the experience
with SARS and MERS.

Bovine coronaviruses (BoCoVs) are

known to
infect several domestic and wild
ruminants (126). BoCoV inflicts neonatal
calf diarrhea in adult cattle, leading to
bloody diarrhea (winter dysentery) and
respiratory disease complex (shipping
fever) in cattle of all age groups (126).
BoCoV-like viruses have been noted in
humans, suggesting its zoonotic potential
as well (127). Feline enteric and feline
infectious peritonitis (FIP) viruses are the
two major feline CoVs (128), where
feline CoVs can affect the
gastrointestinal tract, abdominal cavity
(peritonitis),
respiratory tract, and central nervous
system (128). Canines are also affected
by Cos that fall under different genera,
namely, canine enteric coronavirus in
Alphacoronavirus and canine respiratory
coronavirus in Betacoronavirus, affecting
the enteric and respiratory tract,
respectively (129, 130). IBV, under
Gammacoronavirus, causes diseases of
respiratory, urinary, and reproductive
systems, with
substantial economic losses in chickens
(131, 132). In small laboratory animals,
mouse hepatitis virus. rat
sialodacryoadenitis coronavirus, and
guinea pig and rabbit coronaviruses are
the major Cos associated with disease
manifestations like enteritis.
hepatitis, and respiratory infections (10,
133).

The virus can remain viable on surfaces

for days in favourable atmospheric
conditions but are destroyed in less than
a minute by common disinfectants like
sodium
hypochlorite, hydrogen peroxide etc.
[13]. Infection is acquired either by
inhalation of these droplets or touching
surfaces contaminated by them and then
touching the nose, mouth and eyes. The
virus is also present in the stool and
contamination of the water supply and
subsequent transmission via
aerosolization/feco oral route is also
hypothesized (6]. As per current
information, transplacental transmission
from pregnant women to
their fetus has not been described [14].
However, neonatal disease due to post
natal transmission is described [141. The
incubation period varies from 2 to 14 d
[median 5 d].

Cases continued to increase

exponentially and modelling studies
reported an epidemic doubling time of
1.8 d [101. In fact on the 12th of
February, China changed its definition of
confirmed cases to include patients with
negative/ pending molecular tests but
with clinical, radiologic and
epidemiologic features of COVID-19
leading to an increase in cases by
15,000 in a single day (6]. As of
05/03/2020 96.000 cases worldwide
(80,000 in China) and 87 other countries
and 1 international conveyance (696, in
the cruise ship Diamond Princess parked
off the coast of lapan) have been reported
[2]. It is important to note that while the
number of new cases has reduced in
China lately, they have increased
exponentially in other countries
including South Korea, Italy and Iran.
Of those infected, 20% are in critical
And comprised a small population and.
hence. the possibility of misinterpretation
could arise. However,
in another case study, the authors raised
concerns
overthe
efficacy of hydroxychloroquine-
azithromyein in the treatment of COVID-
19 patients, since no observable effect
was seen when they were used. In some
cases, the treatment was discontinued
due to the prolongation of the QT
interval (307). Hence, further
randomized clinical trials are required
before concluding this matter.
Recently, another FDA-approved
drug, ivermectin, was reported to inhibit
the in vitro replication of SARS-CoV-2.
The findings from this study indicate that
a single treatment of this drug was able
to induce an -5.000-fold reduction in the
viral RNA at 48 h in cell culture. (308).
One of the main disadvantages that limit
the clinical utility of
ivermectin is its potential to cause
cytotoxicity. However, altering the
vehicles used in the formulations, the
pharmacokinetic properties can be
modified, thereby having significant
control over the systemic concentration
of ivermectin (338). Based on the
pharmacokinetic simulation, it was also
found that ivermectin may have limited
therapeutic utility in managing COVID-
19, since the inhibitory concentration that
has to be achieved for effective
anti-SARS-CoV-2 activity is far higher
than the was linked to a family member
and 26 children had history of
travel/residence to Hubei province in
China. All the patients were either
asymptomatic (9%) or had mild disease.
No severe or critical cases were seen.
The most common symptoms were fever
(50%) and cough (38%). All patients
recovered with symptomatic therapy and
there were no deaths. One case of severe
pneumonia and multiorgan dysfunction
in a child has also been
reported (191. Similarly the neonatal
cases that have been reported have
been mild (20].

Diagnosis [21] A suspect case is defined

as one with fever, sore throat and cough
who has history of travel to China or
other areas of persistent local
transmission or
contact with patients with similar
travel history or those with confirmed
of persistent local transmission or contact
with patients with similar
travel history or those with confirmed
COVID-19 infection. However cases
may be asymptomatic or even without
fever. A confirmed case is a suspect
case with a positive molecular test.
Specific diagnosis is by specific
molecular tests on respiratory samples
(throat swab/ nasopharyngeal swab/
sputum/ endotracheal aspirates and
bronchoalveolar lavage). Virus may
also be detected in the stool and in
soverp cases the blood.it must he
remembered that the multiplex PCR
panels currently available do not include
the COVID-19. Commercial tests are
also not available at present. In a suspect
case in India, the appropriate sample has
to be sent to designated
reference labs in India or the National
Institute of Virology in Pune. As the
epidemic progresses, commercial tests
identified angiotensin receptor 2 (ACE,)
as the receptor through which the virus
enters the respiratory mucosa
(11). The basic case reproduction rate
(BCR) is estimated to range from 2 to
6.47 in various modelling studies [11]. In
comparison, the BCR of SARS was 2
and
1.3 for pandemic flu H1N1 2009 [2].