Vaccine is not a sure shot solution, says principal investigator of Covaxin clinical trial at AIIMS


In a conversation with The Daily Guardian, Dr Sanjay Rai, Professor, Community Medicine and principal investigator of Covaxin at AIIMS, speaks about myths and facts related to Covid-19 vaccines. Excerpts:

Q. We have seen vaccinated people are testing Covid positive and lot of people are scared of getting vaccines. Why is it so?

A. Vaccine is not a sure shot solution, it’s a kind of experiment, but these vaccines are approved by regulatory authority. It is scientifically proven that those who haven’t got vaccinated are more prone to virus than vaccinate ones. The efficacy of every vaccine is different. Covaxine’s efficacy was 81% and 78% in first and second trials, respectively. These vaccines have inactivated virus which kills the active viruses. People should come forward and get vaccinated as it’s the best possible way to curb the pandemic.

Q. The second surge was so dreadful and it appeared as if even virus got strengthened fiercer than ever. What’s the prime reason behind it?

A. There are several rumors circulating regarding immunity. It’s a complex mechanism that maintains our immunity in body. Different kinds of immunity exist in our body like, Solar Immunity and Humoral immunity. If a person has been infected with any kind of virus before and later healed then his body is expected to have developed anti-virus agents in body. Such people are not prone to virus and stay safe. Immunoglobulin level is one way to measure immunity of a person. But it’s not the only way in many cases we have observed that people with less IGG level also has good immunity and they are not prone to viruses.

Also, Sero survey is one the best ways to find out which region will be mostly affected. Places where majority of people were infected, there is least possibility of people there to get infected again. Like, Spanish Flu in 1918 and Swine Flu in 2009, where virus died early.

Q. It is being observed that recovered people are getting vaccinated in majority. Is this right ?

A. If it is prescribed then it must have a scientific backing, because we don’t have time for assumptions.

Q. What are the parameters which decide the amount of dose in body?

A. The rate to create anti-bodies in individual’s body decides the dose of vaccines. Elderly and kids have similar kind of dose.

Q. Do you think vaccinated people will need the booster?

A. We are still examining the situation right now and haven’t got any such evidence where we can prescribe immunity booster for those who are vaccinated.

Q. On what circumstances immunity passport should be issued?

A. I believe people who have recovered from the virus are the safest amongst all. Such people should be eligible for immunity passports as they are least to virus and won’t spread it further.

Q. What should be the standard gap between two doses?

A. Research says that standard gap should be of four weeks and maximum it should go till 12 weeks. But the gap is proportional to less effectiveness of the virus.