Coronaviruses can cause respiratory illnesses ranging from mild to lethal in humans and other animals. COVID-19 is caused by the SARS-CoV-2 virus and was first detected in Wuhan, China in late 2019. It has since caused a global pandemic. India has had over 26 million confirmed cases as of May 2021, second only to the US. COVID-19 spreads mainly through respiratory droplets and can be transmitted from pre-symptomatic or asymptomatic carriers. Symptoms range from mild to severe and include fever, cough and shortness of breath. Diagnosis involves PCR or antibody testing. Treatment focuses on symptom relief, and those with mild or no symptoms can recover with home isolation if proper precautions are followed.

1. CORONA VIRUS
PRESENTED BY
R.PRIYA
Wear Mask

2. INTRODUCTION
Coronaviruses are a group of related RNA viruses that cause diseases in mammals and
birds. In humans and birds, they cause respiratory tract infections that can range from mild
to lethal. Mild illnesses in humans include some cases of the common cold (which is also
caused by other viruses, predominantly rhinoviruses), while more lethal varieties can cause
SARS,MERS,, and COVID-19. In cows and pigs they cause diarrhea,, while in mice they
cause hepatitis and encephalomyelitis. The COVID-19 pandemic in India is part of
theworld wide pandamic of coronavirus disease 2019. (COVID-19) caused by severe acute
respiratorynsyndrome coronavirus 2 (SARS-CoV-2). The first case of COVID-19 in India ,
which originated from china, was reported on 30 January 2020, India currently has the
largest number of conformed cases in Asia. As of 23 May 2021, India has the second-
highest number of confirmed cases in the world (after the United States ) with 26.7 million
reported cases of COVID-19 infection and the third-highest number of COVID-19 deaths
(after the United States and Brazil) at 307,231 deaths.
The first cases of COVID-19 in India were reported in the towns of Thissure, Alappula and
Kasargod,all in the stateof Kerala, among three Indian medical students who had returned
from wuhun. Lockdowns were announced in Kerala on 23 March, and in the rest of the
country on 25 March. By mid-May 2020, five cities accounted for around half of all reported
cases in the country:Mumbai, Delhi, Ahmedabad,Chennai andThane.
first known infections from SARS-CoV-2 were discovered in Wuhan, China. The original
source of viral transmission to humans remains unclear, as does whether the virus became
pathogenic before or after the spillover event.

3. DEFINITION
COVID-19 is a disease caused by a new strain of coronavirus. 'CO' stands for
corona, 'VI' for virus, and 'D' for disease. Formerly, this disease was referred to
as '2019 novel coronavirus' or '2019-nCoV.'
5/27/2021 10:38 GMT — Number of COVID-19 cases by country
1.United States: 33,190,560
2.India: 27,369,093
3.Brazil: 16,274,695
4.France: 5,683,143
5.Turkey: 5,212,123

4. TYPES OF CORONA VIRUS
•229E (alpha)
•NL63 (alpha)
•OC43 (beta)
•HKU1 (beta.
•MERS-CoV, a beta virus that causes Middle East respiratory syndrome
(MERS)
•SARS-CoV, a beta virus that causes severe acute respiratory syndrome
(SARS)
•SARS-CoV-2, which causes COVID-19.

5. CAUSES
COVI Variants
Main article: Variants of SARS-CoV-2
Several variants of SARS-CoV-2 have emerged that are spreading globally. The most
currently prevalent, all of which share the more infectious D614G Mutation, are;
• B.1.1.7 first detected in the UK, which has spread to over 120 countries
• P.1 ,first detected in Brazil, which has spread to more than 50 countries
•B.1.351, first detected in South Africa, which has spread to over 80 countries
D-19 is caused by the virus SARS-CoV-2.
a special focus update is provided on SARS-CoV-2 Variants of Interest (VOIs) and Variants of Concern (VOCs)
B.1.1.7, B.1.351, P.1, and B.1.617. This includes updates on emerging evidence surrounding the phenotypic
characteristics of VOCs (transmissibility, disease severity, risk of reinfection, and impacts on diagnostics and
vaccine performance), as well as updates on the geographic distribution of VOCs.

6. MODE OF TRANSMISSION
•Current evidence suggests that the virus spreads mainly between people who are in
close contact with each other, typically within 1 metre (short-range). A person can be
infected when aerosols or droplets containing the virus are inhaled or come directly
into contact with the eyes, nose, or mouth. The virus can also spread in poorly
ventilated and/or crowded indoor settings, where people tend to spend longer periods
of time. This is because aerosols remain suspended in the air or travel farther than 1
metre (long-range).
People may also become infected by touching surfaces that have been contaminated
by the virus when touching their eyes, nose or mouth without cleaning their hands.
Further research is ongoing to better understand the spread of the virus and which
settings are most risky and why. Research is also under way to study virus variants
that are emerging and why some are more transmissible. For updated information on
SARS-CoV-2 variants, Laboratory data suggests that infected people appear to be
most infectious just before they develop symptoms (namely 2 days before they
develop symptoms) and early in their illness. People who develop severe disease can
be infectious for longer.
While someone who never develops symptoms can pass the virus to others, it is still
not clear how frequently this occurs and more research is needed in this area.

7. PATHOPHYSIOLOGY

8. PATHOPHYSIOLOGY

9. SIGNS SYMPTOMS
Severity of disease Presentation
Asymptomatic
•No clinical symptoms
•Positive nasal swab test
•Normal chest X-ray
Mild illness
•Fever, sore throat, dry cough, malaise and body aches or
•Nausea, vomiting, abdominal pain, loose stools,
Moderate illness
•Symptoms of pneumonia (persistent fever and cough)
without hypoxemia
•Significant lesions on high-resolution CT chest
Severe illness •Pneumonia with hypoxemia (SpO2 < 92%)
Critical state
•Acute respiratory distress syndrome, along with shock,
coagulation defects, encephalopathy, heart failure and
acute kidney injury

10. SIGNS SYMPTOMS
ASYMPTOMATIC PHASE
The SARS-CoV-2 which is received via respiratory aerosols binds to the nasal epithelial cells in the upper respiratory tract. The main host
receptor for viral entry into cells is the ACE-2, which is seen to be highly expressed in adult nasal epithelial cells. The virus undergoes local
replication and propagation, along with the infection of ciliated cells in the conducting airways. This stage lasts a couple of days and the
immune response generated during this phase is a limited one. In spite of having a low viral load at this time, the individuals are highly
infectious, and the virus can be detected via nasal swab testing.
INVASION AND INFECTION OF THE UPPER RESPIRATORY TRACT
In this stage, there is migration of the virus from the nasal epithelium to the upper respiratory tract via the conducting airways. Due to the
involvement of the upper airways, the disease manifests with symptoms of fever, malaise and dry cough. There is a greater immune response
during this phase involving the release of C-X-C motif chemokine ligand 10 (CXCL-10) and interferons (IFN-β and IFN-λ) from the virus-
infected cells. The majority of patients do not progress beyond this phase as the mounted immune response is sufficient to contain the
spread of infection.
INVOLVEMENT OF THE LOWER RESPIRATORY TRACT AND PROGRESSION TO Acute RESPIRATORY DISTRESS SYNDROME
(ARDS)
About one-fifth of all infected patients progress to this stage of disease and develop severe symptoms. The virus invades and enters the type
2 alveolar epithelial cells via the host receptor ACE-2 and starts to undergo replication to produce more viral Nucleocapsids. The virus-laden
pneumocytes now release many different cytokines and inflammatory markers such as interleukins (IL-1, IL-6, IL-8, IL-120 and IL-12), tumour
necrosis factor-α (TNF-α), IFN-λ and IFN-β, CXCL-10, monocyte chemoattractant protein-1 (MCP-1) and macrophage inflammatory protein-
1α (MIP-1α). This ‘cytokine storm’ acts as a chemoattractant for neutrophils, CD4 helper T cells and CD8 cytotoxic T cells, which then begin
to get sequestered in the lung tissue. These cells are responsible for fighting off the virus, but in doing so are responsible for the subsequent
inflammation and lung injury. The host cell undergoes apoptosis with the release of new viral particles, which then infect the adjacent type 2
alveolar epithelial cells in the same manner. Due to the persistent injury caused by the sequestered inflammatory cells and viral replication
leading to loss of both type 1 and type 2 pneumocytes, there is diffuse alveolar damage eventually culminating in an acute respiratory
distress syndrome.
VIRAL TRANSMISSION AND CLINICAL FEATURES
COVID-19 virus is mainly spread from person to person via respiratory droplet transmission, which occurs when a person is in close contact
with someone who is actively coughing or sneezing. This occurs through exposure of the mucosal surfaces of the host, that is, eyes, nose
and mouth, to the incoming infective respiratory droplets. Transmission of the virus may also occur through fomites used by or used on the
infected individual such as bedsheets, blankets, kitchen utensils, thermometers and stethoscopes. Airborne transmission has not been
reported for COVID-19, except in specific circumstances in which procedures that generate aerosols are performed, that is, endotracheal
intubation, bronchoscopy, open suctioning, nebulisation with oxygen, bronchodilators or steroids, bag and mask ventilation before intubation,
tracheostomy and cardiopulmonary resuscitation.
The incubation period of COVID-19, which is the time period from exposure to the virus to symptom onset, is 5–6 days, but can be up to

11. DIAGNOSTIC EVALUATION
Investigation Remarks
Basic blood work
•Decreased WBC count as well as lymphopenia
•Increased levels of AST and ALT, LDH and CRP
•Increased D-dimer
•Increased PT/INR
Molecular testing via RT-PCR
•Techniques employed are RT-PCR and rRT-PCR which amplify viral genetic material obtained via nasal swab
•Poor sensitivity
•Repeat testing required for verification of viral clearance
Chest X-ray
•No significant findings early in the disease
•Bilateral patchy opacities in advanced disease
HRCT chest
•Multifocal bilateral ‘ground or ground-glass’ areas associated with consolidation areas with patchy
distribution
•‘Reverse halo’ sign
•Cavitation, calcification and lymphadenopathy
•High sensitivity for COVID-19 diagnosis
Serology/antibody testing •Further research still required for a proper/sensitive antibody test
•ALT, alanine amino-transferase; AST, aspartate amino-transferase; CRP, C reactive protein; HRCT, high-
resolution CT; INR, international randomised ratio; LDH, lactate dehydrogenase; PT, prothrombin time; RT-
PCR, reverse-transcription PCR; rRT-PCR, real-time reverse-transcription PCR; WBC, white blood count.

12. TREATMENT FOR CORONA
Self-care
Asymptomatic cases, mild cases of COVID-19:
Isolate yourself in a well ventilated room.
Use a triple layer medical mask, discard mask after 8 hours of use or earlier if they become wet or visibly soiled. In the event of a
caregiver entering the room, both caregiver and patient may consider using N 95 mask.
Mask should be discarded only after disinfecting it with 1% Sodium Hypochlorite.
Take rest and drink a lot of fluids to maintain adequate hydration.
Follow respiratory etiquettes at all times.
Frequent hand washing with soap and water for at least 40 seconds or clean with alcohol-based sanitizer.
Don’t share personal items with other people in the household.
Ensure cleaning of surfaces in the room that are touched often (tabletops, doorknobs, handles, etc.) with 1% hypochlorite solution.
Monitor temperature daily.
Monitor oxygen saturation with a pulse oximeter daily.
Connect with the treating physician promptly if any deterioration of symptoms is noticed.
Instructions for caregivers:
Mask: The caregiver should wear a triple layer medical mask. N95 mask may be considered when in the same room with the ill
person.
Hand hygiene: Hand hygiene must be ensured following contact with ill person or patient’s immediate environment.
Exposure to patient/patient’s environment: Avoid direct contact with body fluids of the patient, particularly oral or respiratory
secretions. Use disposable gloves while handling the patient. Perform hand hygiene before and after removing gloves.

13. Cont.…
Treatment for patients with mild/asymptomatic disease in home isolation
Patients must be in communication with a treating physician and promptly report in case of
any worsening.
Continue the medications for other co-morbid illness after consulting the treating physician.
Patients to follow symptomatic management for fever, running nose and cough, as
warranted.
Patients may perform warm water gargles or take steam inhalation twice a day.
When to seek immediate medical attention:
Difficulty in breathing
Dip in oxygen saturation (SpO2 < 94% on room air)
Persistent pain/pressure in the chest
Mental confusion or inability to arouse

14. Revised guidelines for Home Isolation of mild /asymptomatic COVID-19 cases
1. Background The guidelines are in supersession to the guidelines issued on the subject on 2nd July, 2020.
As per the guidelines, the patients who are clinically assigned to be mild /asymptomatic are recommended for home
isolation.
2. Asymptomatic cases; mild cases of COVID-19 The asymptomatic cases are laboratory confirmed cases not
experiencing any symptoms and having oxygen saturation at room air of more than 94%. Clinically assigned mild cases
are patients with upper respiratory tract symptoms (&/or fever) without shortness of breath and having oxygen
saturation at room air of more than 94%.
3. Patients eligible for home isolation i. The patient should be clinically assigned as mild/ asymptomatic case by the
treating Medical Officer. ii. Such cases should have the requisite facility at their residence for self-isolation and for
quarantining the family contacts. iii. A care giver should be available to provide care on 24 x7 basis. A communication
link between the caregiver and hospital is a prerequisite for the entire duration of home isolation. iv. Elderly patients
aged more than 60 years and those with co-morbid conditions such as Hypertension, Diabetes, Heart disease, Chronic
lung/liver/ kidney disease, Cerebro-vascular disease etc shall only be allowed home isolation after proper evaluation by
the treating medical officer. v. Patients suffering from immune compromised status (HIV, Transplant recipients, Cancer
therapy etc.) are not recommended for home isolation and shall only be allowed home isolation after proper evaluation
by the treating medical officer. vi. The care giver and all close contacts of such cases should take Hydroxychloroquine
prophylaxis as per protocol and as prescribed by the treating medical officer. vii. In addition, the guidelines on home-
quarantine for other members available at: https://www.mohfw.gov.in/pdf/Guidelinesforhomequarantine.pdf, shall be
also followed.
Cont.…

15. 4. Instructions for the patient
i. Patient must isolate himself from other household members, stay in the identified room and away from other people in
home, especially elderlies and those with co-morbid conditions like hypertension, cardiovascular disease, renal disease etc. ii.
The patient should be kept in a well-ventilated room with cross ventilation and windows should be kept open to allow fresh air
to come in. iii. Patient should at all times use triple layer medical mask. Discard mask after 8 hours of use or earlier if they
become wet or visibly soiled. In the event of care giver entering the room, both care giver and patient may consider using N 95
mask. iv. Mask should be discarded only after disinfecting it with 1% Sodium Hypochlorite. v. Patient must take rest and drink
lot of fluids to maintain adequate hydration. vi. Follow respiratory etiquettes at all times. vii. Frequent hand washing with soap
and water for at least 40 seconds or clean with alcohol-based sanitizer. viii. Don’t share personal items with other people in the
household. ix. Ensure cleaning of surfaces in the room that are touched often (tabletops, doorknobs, handles, etc.) with 1%
hypochlorite solution. x. Self-monitoring of blood oxygen saturation with a pulse oximeter is strongly advised. xi. The patient
will self-monitor his/her health with daily temperature monitoring and report promptly if any deterioration of symptom as
given below is noticed.
5. Instructions for caregivers
i. Mask: o The caregiver should wear a triple layer medical mask. N95 mask may be considered when in the same room with
the ill person. o Front portion of the mask should not be touched or handled during use. o If the mask gets wet or dirty with
secretions, it must be changed immediately. o Discard the mask after use and perform hand hygiene after disposal of the
mask. o He/she should avoid touching own face, nose or mouth.
ii. Hand hygiene o Hand hygiene must be ensured following contact with ill person or his immediate environment. o Hand
hygiene should also be practiced before and after preparing food, before eating, after using the toilet, and whenever hands
look dirty. o Use soap and water for hand washing at least for 40 seconds. Alcohol-based hand rub can be used, if hands are
not visibly soiled. o After using soap and water, use of disposable paper towels to dry hands is desirable. If not available, use
dedicated clean cloth towels and replace them when they become wet. o Perform hand hygiene before and after removing
gloves.
Cont.…

16. iii. Exposure to patient/patient’s environment o Avoid direct contact with body fluids of the patient, particularly oral or
respiratory secretions. Use disposable gloves while handling the patient. o Avoid exposure to potentially contaminated items in
his immediate environment (e.g. avoid sharing cigarettes, eating utensils, dishes, drinks, used towels or bed linen). o Food must
be provided to the patient in his room. Utensils and dishes used by the patient should be cleaned with soap/detergent and water
wearing gloves. The utensils and dishes may be re-used. o Clean hands after taking off gloves or handling used items. Use triple
layer medical mask and disposable gloves while cleaning or handling surfaces, clothing or linen used by the patient. o Perform
hand hygiene before and after removing gloves. iv. Biomedical Waste disposal o Effective waste disposal shall be ensured so as to
prevent further spread of infection within household. The waste (masks, disposable items, food packets etc.) should be disposed
of as per CPCB guidelines (available at: http://cpcbenvis.nic.in/pdf/1595918059_mediaphoto2009.pdf)
6. Treatment for patients with mild /asymptomatic disease in home isolation
i. Patients must be in communication with a treating physician and promptly report in case of any deterioration. ii. Continue
the medications for other co-morbid illness after consulting the treating physician. iii. Patients to follow symptomatic
management for fever, running nose and cough, as warranted. iv. Patients may perform warm water gargles or take steam
inhalation twice a day. v. If fever is not controlled with a maximum dose of Tab. Paracetamol 650mg four times a day, consult
the treating doctor who may consider advising other drugs like non-steroidal anti-inflammatory drug (NSAID) (ex: Tab.
Naproxen 250 mg twice a day). vi. Consider Tab Ivermectin (200 mcg/kg once a day, to be taken empty stomach) for 3-5day
vii. Inhalational Budesonide (given via inhalers with spacer at a dose of 800 mcg twice daily for 5 to 7 days) to be given
if symptoms (fever and/or cough) are persistent beyond 5 days of disease onset. viii. The decision to administer Remdesivir
or any other investigational therapy must be taken by a medical professional and administered only in a hospital setting. Do
not attempt to procure or administer Remdesivir at home. ix. Systemic oral steroids not indicated in mild disease. If
symptoms persist beyond 7 days (persistent fever, worsening cough etc.) consult the treating doctor for treatment with low
dose oral steroids. x. In case of falling oxygen saturation or shortness of breath, the person should require hospital
admission and seek immediate consultation of their treating physician/surveillance team.
Cont.…

17. 7. When to seek medical attention Patient / Care giver will keep monitoring their health. Immediate medical attention must
be sought if serious signs or symptoms develop. These could include. i. Difficulty in breathing, ii. Dip in oxygen saturation
(SpO2 < 94% on room air) iii. Persistent pain/pressure in the chest, iv. Mental confusion or inability to arouse, 8. When to
discontinue home isolation Patient under home isolation will stand discharged and end isolation after at least 10 days have
passed from onset of symptoms (or from date of sampling for asymptomatic cases) and no fever for 3 days. There is no need
for testing after the home isolation period is over. 9. Role of State/District Health Authorities i. States/ Districts should
monitor all cases under home isolation. ii. The health status of those under home isolation should be monitored by the field
staff/surveillance teams through personal visit along with a dedicated call centre to follow up the patients on daily basis. iii.
The clinical status of each case shall be recorded by the field staff/call centre (body temperature, pulse rate and oxygen
saturation). The field staff will guide the patient on measuring these parameters and provide the instructions (for patients and
their care givers). This mechanism to daily monitor those under home isolation shall be strictly adhered to. iv. Details about
patients under home isolation should also be updated on COVID-19 portal and facility app (with DSO as user). Senior State
and District officials should monitor the records up dation. v. A mechanism to shift patient in case of violation or need for
treatment has to be established and implemented. Sufficient dedicated ambulances for the same shall be organised. Wide
publicity for the same shall also be given to the community. vi. All family members and close contacts shall be monitored and
tested as per protocol by the field staff. vii. Patient on home isolation will be discharged from treatment as indicate above.
These discharge guidelines shall be strictly adhered to.
Cont.…

18. EUAs allow products that haven’t received FDA approval to be used in circumstances where there are no suitable
FDA-approved alternatives.
The COVID-19 medications that have received EUAs are:
•bamlanivimab
•a combination of bamlanivimab and etesevimab (etesevimab must be administered in combination with
bamlanivimab)
•casirivimab and imdevimab, which must be administered together
•the oral medication baricitinib (Olumiant), which must be administered with remdesivir
•COVID-19 convalescent plasma
•Fresenius Kabi Propoven 2%, an IV sedative
•Fresenius Medical, multiFiltrate PRO System and multiBic/multiPlus solutions for people who need continuous renal
replacement therapy (CRRT)
•REGIOCIT replacement solution with citrate for people who need CRRT
Remdesivir has also received an EUA to treat children who are under 12 years old or have a low body weight.
Bamlanivimab, etesevimab, casirivimab, and imdevimab are IV infusion therapies. Unlike remdesivir, they’re
administered as outpatient therapy and intended for people who have less severe disease. Their purpose is to help
reduce the risk of hospitalization.
The other medications are all intended for people who’ve been hospitalized or are at risk for hospitalization.
A January 2021 study on convalescent plasma looked at effects on adults age 65 and older who’d tested positive for
SARS-CoV-2 and were symptomatic. Researchers found that the group who’d received convalescent plasma within
72 hours of the onset of symptoms were 48 percent less likely to develop COVID-19 than the group who’d received
a placebo.
Convalescent plasma must be administered early into the onset of symptoms to be effective.
In February 2021, the FDATrusted Source updated its guidance on the use of convalescent plasma. It stated that

19. Other treatments
If your symptoms are more severe, supportive treatments may be given by your doctor or at a hospital. This type of
treatment may involve:
•fluids to reduce the risk of dehydration,medication to reduce a fever,supplemental oxygen in more severe cases
People who have a hard time breathing due to COVID-19 may need a ventilator.
Here are some of the treatment options that have been investigated for protection against SARS-CoV-2 and
treatment of COVID-19 symptoms.
 Chloroquine
Chloroquine is a drug that’s used to fight malaria and autoimmune diseases. It’s been in use for more than 70 years
and is generally considered safe.
At the beginning of the pandemic, researchersTrusted Source discovered that the drug effectively fought the SARS-
CoV-2 virus in test tube studies.
However, a February 2021 literature review concluded that there wasn’t enough evidence to deem it effective. The
authors of the review also suggested that researchers end clinical trials examining chloroquine’s role as a COVID-19
treatment.
 Lopinavir and ritonavir
Lopinavir and ritonavir are sold under the name Kaletra and are designed to treat HIV.
In early 2020, a 54-year-old South Korean man was given a combination of these two drugs and had a significant
reduction in his levels of the coronavirus.
Afterward, the World Health Organization (WHO) suggested that there may be benefits to using Kaletra in
combination with other drugs.
According to a February 2021 study published in the New England Journal of Medicine and conducted by the WHO
and its partners, this drug combination has little to no effect on people hospitalized with COVID-19. Taking the
medication didn’t definitively decrease mortality rates, ventilation rates, or the duration of their hospital stays.

20.  Favilavir (favipiravir)
In February 2020, China approved the use of the antiviral drug favilavir to treat symptoms of COVID-19.
The drug was initially developed to treat inflammation in the nose and throat. It’s also commonly known
as favipiravir.
The early word was that the drug was shown to be effective in treating COVID-19 symptoms in a clinical
trial of 70 people.
A january 2021study in ACS Central Science concluded that favilavir and the antiviral drug ribavirin
weren’t as effective as remdesivir. Despite its early approval in China, favilavir has yet to be authorized
or approved by the FDA.

21. ]
Preventive measures to reduce the chances of infection include getting vaccinated, staying at
home, wearing a mask in public, avoiding crowded places, keeping distance from others,
ventilating indoor spaces, managing potential exposure durations, washing hands with soap and
water often and for at least twenty seconds, practising good respiratory hygiene, and avoiding
touching the eyes, nose, or mouth with unwashed hands.
Those diagnosed with COVID-19 or who believe they may be infected are advised by the CDC
to stay home except to get medical care, call ahead before visiting a healthcare provider, wear a
face mask before entering the healthcare provider's office and when in any room or vehicle with
another person, cover coughs and sneezes with a tissue, regularly wash hands with soap and
water and avoid sharing personal household items.
Prevention
Further information: COVID-19 § Prevention, Face masks during the COVID-19 pandemic, and Social
distancing measures related to the COVID-19 pandemic

22. Vaccines
Main article: COVID-19 vaccine
See also: History of COVID-19 vaccine development and Deployment of COVID-19
vaccine
In Phase III trials, several COVID-19 vaccines have demonstrated efficacy as high as 95% in preventing
symptomatic COVID-19 infections. As of April 2021, 16 vaccines are authorized by at least one national regulatory
authority for public use: three RNA vaccines (Pfizer–BioNTech and Moderna), seven conventional inactivated
vaccines (BBIBP-CorV, CoronaVac, Covaxin, WIBP-CorV, CoviVac, Minhai-Kangtai and QazVac), five viral vector
vaccines (Sputnik Light, Sputnik V, Oxford–AstraZeneca, Convidecia, and Johnson & Johnson), and two protein
subunit vaccines (EpiVacCorona and RBD-Dimer).[137][failed verification] In total, as of March 2021, 308 vaccine
candidates are in various stages of development, with 73 in clinical research, including 24 in Phase I trials, 33
in Phase I–II trials, and 16 in Phase III development,Many countries have implemented phased distribution plans
that prioritize those at highest risk of complications, such as the elderly, and those at high risk of exposure and
transmission, such as healthcare workers.[138] Single dose interim use is under consideration in order to extend
vaccination to as many people as possible until vaccine availability improves.
On 21 December 2020, the European Union approved the Pfizer BioNTech vaccine. Vaccinations began to be
administered on 27 December 2020. The Moderna vaccine was authorized on 6 January 2021 and
the AstraZeneca vaccine was authorized on 29 January 2021.

23. On 4 February 2020, US Secretary of Health and Human Services Alex Azar published a notice of declaration
under the Public Readiness and Emergency Preparedness Act for medical countermeasures against COVID-19,
covering "any vaccine, used to treat, diagnose, cure, prevent, or mitigate COVID-19, or the transmission of SARS-
CoV-2 or a virus mutating therefrom", and stating that the declaration precludes "liability claims alleging negligence
by a manufacturer in creating a vaccine, or negligence by a health care provider in prescribing the wrong dose,
absent willful misconduct". The declaration is effective in the United States through 1 October 2024,On 8
December it was reported that the AstraZeneca vaccine is about 70% effective, according to a study.
Vaccines