Explained | Why Haryana Minister Anil Vij Who Volunteered For Bharat Biotech's COVID Vaccine Trial Tested Positive?

Vij was the first volunteer of Covaxin's phase-3 trial in Haryana which started in November. Bharat Biotech is testing the vaccine in a late stage trial on 25,800 volunteers across in the country.

Viswanath Pilla

Dec 5, 2020 / 10:59 PM IST

File image of Haryana minister and BJP leader Anil Vij

Anil Vij, the Haryana Health Minister who was administered a trial dose of Bharat Biotech's COVID-19 vaccine Covaxin, on November 20 at a hospital in Ambala, has been tested positive for Coronavirus. Vij was admitted in Civil Hospital, Ambala. He advised all those who came in close contact to test for the virus.

Incidentally, Vij was the first volunteer of Covaxin's phase-3 trial in Haryana which started in November. Bharat Biotech is testing the vaccine in a late stage trial on 25,800 volunteers across in the country.

Vij testing postive even after receiving Covaxin, has raised many questions on the effectiveness of the vaccine.

Here is a explainer, on possible reason behind him testing positive

Did he get vaccine or placebo?

COVID-19 Vaccine

Frequently Asked Questions

How does a vaccine work?

A vaccine works by mimicking a natural infection. A vaccine not only induces immune response to protect people from any future COVID-19 infection, but also helps quickly build herd immunity to put an end to the pandemic. Herd immunity occurs when a sufficient percentage of a population becomes immune to a disease, making the spread of disease from person to person unlikely. The good news is that SARS-CoV-2 virus has been fairly stable, which increases the viability of a vaccine.

How many types of vaccines are there?

There are broadly four types of vaccine — one, a vaccine based on the whole virus (this could be either inactivated, or an attenuated [weakened] virus vaccine); two, a non-replicating viral vector vaccine that uses a benign virus as vector that carries the antigen of SARS-CoV; three, nucleic-acid vaccines that have genetic material like DNA and RNA of antigens like spike protein given to a person, helping human cells decode genetic material and produce the vaccine; and four, protein subunit vaccine wherein the recombinant proteins of SARS-COV-2 along with an adjuvant (booster) is given as a vaccine.

What does it take to develop a vaccine of this kind?

Vaccine development is a long, complex process. Unlike drugs that are given to people with a diseased, vaccines are given to healthy people and also vulnerable sections such as children, pregnant women and the elderly. So rigorous tests are compulsory. History says that the fastest time it took to develop a vaccine is five years, but it usually takes double or sometimes triple that time.

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Since the trial is double blinded, which means neither the investigator who is administering the jab nor the participant who received knows whether it is a vaccine or a placebo. To verify whether Vij got a vaccine or placebo, the trial needs to unblinded for that particular participant, but this usually doesn't happen, until and unless it is a case of serious adverse event. Vij who had volunteered for the Phase-3 trial of Covaxin, has 50 percent chance of getting the vaccine shot. Bharat Biotech the sponsor of Covaxin trial hasn't clarified, on whether the jab given to Vij as part of trial was COVID vaccine or not.

Did he get the second dose?

Bharat Biotech says that clinical trials are based on a two-dose schedule, given 28 days or four weeks apart. "The vaccine efficacy will be determined two weeks after the second dose," the company said. Since Vij got his first dose on November 20, there is no possibility of him getting a second dose as per the dosing schedule.

What if Vij got the vaccine shot and not placebo?

Let's assume that even if Vij got two doses of the COVID vaccine, that doesn't mean that he is 100 percent likely to be protected against COVID-19. A few people from vaccine arm (vaccine arm in clinical trial means a volunteer who gets the vaccine and not placebo) are still at risk to contract COVID-19 infection. The efficacy of the vaccine in preventing COVID-19 is analysed after certain threshold of trial participants test positive to COVID-19. For a vaccine to have around 50 percent efficacy, for example if the threshold number is 32, the vaccinated arm should have 10 people and the unvaccinated or placebo arm should be having 22 participants. The point here is that there will always be some participants even in the vaccinated arm who will test positive. At this point of time we don't know the efficacy of Bharat Biotech's Covaxin.

Lesson for clinical trial volunteers?

Participation in a clinical trial to test an experimental COVID vaccine is a service to the nation. And one should not be in the false assumption that participating in a clinical trial makes the volunteer COVID free. So, even if one is vaccinated the participant must keep wearing masks, maintain hand hygiene and also be mindful of physical distance.

Viswanath Pilla is a business journalist with 14 years of reporting experience. Based in Mumbai, Pilla covers pharma, healthcare and infrastructure sectors for Moneycontrol.

TAGS: #Business #Companies #coronavirus #Health

first published: Dec 5, 2020 10:59 pm