COVISHIELD, COVAXIN, SPUTNIK V AND BOOSTER DOSES

There are many queries raised by individuals who want to be vaccinated against coronavirus. They are always interested in knowing which vaccine will give them the best possible immunity against coronavirus infection. They are concerned about a booster dose after 2 vaccines. Some individuals visiting the US are always concerned about Pfizer’s vaccine, as vaccines in India are not used there.

What are the most notable benefits of vaccination?

Vaccines have brought a ray of hope in human beings exposed to the coronavirus in this terrible pandemic. A vaccine once injected into your body strengthens your immune system so as to prevent COVID-19 disease to a large extent. If infected, the vaccinated individual is unlikely to become serious and thus may not require aggressive medical treatment. He may not require Oxygen therapy, Ventilatory support, and in fact, his chances of death due to coronavirus will be reduced to a very large extent. The virus if it enters your body will not multiply rapidly and thus will not mutate. The person infected is less likely to become a carrier of the virus.

Which vaccines are currently permitted in India?

Covaxin produced by Bharat Biotech, Covishield produced by Serum Institute of India, Sputnik V produced by Gamely Institute, Moscow is commonly available in India for mass vaccination.
What is Covishield? This is primarily the Indian version of the Oxford-Astra-Zenica vaccine and is made from a weakened version of adenovirus. The virus is originally taken in front of Chimpanzees and is further modified to replicate coronavirus. Once the vaccine is injected, it starts producing antibodies and thus prepares the immune system to prevent the damage caused by a coronavirus.

What about Covaxin?

This is India’s first indigenous vaccine. This is manufactured by Bharat Biotech in collaboration with the Indian Council of Medical Research. It contains a dead virus that cannot undergo mutation or replicate further. It is also a two-dose vaccine.

What about Sputnik V?

It is produced by using a cold virus as a carrier, and small fragments of coronavirus are injected into our bodies. The body launches an antibody response to the genetically modified virus. It requires 2-8 degrees centigrade for storage and hence can be acceptable in India. The two different jabs are developed with different vectors, to target distinctive spikes of the virus. This makes it highly effective in fighting different mutants of the virus and provides much greater protection.

What are the two variants of virus SARS COV 2 of major concern?

The Delta variant is nearly twice as contagious as ear-lier variants and might cause more severe illness. The greatest risk is in unvaccinated individuals. Vaccinated individuals can get breakthrough infections. These individuals spread COVID-19 for a shorter period than those unvaccinated. Research suggests that COVID-19 vaccines are slightly less effective against the Delta variant than the Pfizer- BioNTech, Moderna, and Jansen/Johnson and Johnson. However, those available in India still appear to provide protect Lion against severe Covid 19.

What about the Omicron variant and vaccination?

This spreads more easily than the Delta variant. But it may not cause severe disease. Individuals fully vaccinated can still get breakthrough infections and spread the virus to others. However, vaccination against coronavirus is expected to prevent serious illness. According to Pfizer, a booster dose can prevent serious illness. The Omicron variant may reduce the effectiveness of some monoclonal antibody treatments.

What about Pfizer vaccination in the US after Covishield or Covaxin vaccination in India?

Recent research suggests that people who got COVID-19 in 2020 and then received mRNA vaccines produce very high levels of antibodies that are likely effective against the current and possibly future variants. Some scientists call this a hybrid immunity. Ultimately, which is a better vaccine? While Covishield. Covaxin, Sputnik V, and Moderna come with their own pros and cons, there is no one better than the other. All are equally safe to use and have been approved by the Drugs Controller General of India (DGCI). In light of the present situation, the best option is to get two jabs of any currently available vaccine as early as possible. We have no choice. Whether it is Covishield, Covaxin, Sputnik V, or Moderna, the best way forward is to simply get vaccinated as soon as possible.

What about the booster, that is the third dose?

In a recent meeting of experts, booster dose cannot be recommended without clinical trials. The application of the Serum Institute of India has been kept pending in spite of millions of doses in reserve. In many countries, booster doses have been approved. The vaccine effectiveness gradually reduces in the general population. There is logic in the administration of booster doses, particularly to the front-line health workers and the high-risk population. The medical fraternity is eagerly waiting for a decision in this regard. There is a serious concern about the Omicron virus. The cases are doubling every 2-3 days, particularly in the US. There is 3 fold higher transmission of the delta virus. There is reduced vaccine effectiveness and monoclonal anti• bodies are less effective. As per UK data, there is a possibility of 2.5 times the chance of reinfection after conventional vaccination. Under these circumstances, the case of a third dose that is a booster dose may be important. A quick decision in this regard is expected.

Categories : COVID-19

Dr Jay Deshmukh is Chief Physician and Director, Sunflower Hospital, Nagpur Honorary Physician to Honorable Governor of Maharashtra and PondicherryCentral. Dr Jay Deshmukh is an M.B.B.S., M.C.P.S., F.C.P.S., M.N.A.M.S., MD From Internal Medicine – Bombay and New Delhi.

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