Is a third vaccine booster dose needed? 7 experts weigh in

Source: AP

Serum Institute of India (SII) Chairman Cyrus Poonawalla’s statement that a third or booster dose of Covishield is needed six months after the second dose of the vaccine, has elicited varying responses from the community of epidemiologists, biologists, virologists, and noted COVID-19 experts.

Many of them believe a third dose is not needed, some with significant caveats.

The head of one of the largest vaccine companies in the world, Poonawalla said last week that he and several SII employees had taken the third dose of Covishield, AstraZeneca's vaccine against COVID-19, a PTI report said.

"After six months, the antibodies go down and that is why I have taken the third dose. We have given the third dose to our 7,000-8,000 SII employees. For those who have completed the second dose, it is my request to take a booster dose (third dose) after six months," the news agency reported, quoting Poonawalla.

According to a Ministry of Health press release on August 18, 56.06 crore vaccine doses have been administered so far under the nationwide vaccine drive. India reported 35,178 new cases in the last 24 hours, the release said, adding that the active cases constituted 1.14 percent of total cases, the lowest since March 2020.

According to other estimates, as of the first week of August, roughly 11.40 percent of the adult population and 7.87 percent of the total population of India had been vaccinated.

Experts remain divided on the question of a third vaccine. While most of them find the idea a bit far-fetched, given the realities of India, others feel that since the virus is here to stay, a third, fourth or subsequent dose is a given, under the circumstances. Moneycontrol talked to seven leading experts to get their take on what seemed like an idea that has the potential to set the cat among the pigeons.

Shahid Jameel, Virologist, Ashoka University, Sonipat:

People are jumping the gun. There are no studies or findings as yet, which suggest that a third dose or booster dose will help in countering coronavirus. Ideally, a third dose is not needed. It would be safe to say that while a third dose will not help, it could certainly cause no harm either. It is like saying three doses are better than two or two doses are better than one.

Dr Alex Thomas, National President, Association of Healthcare Providers (AHPI)

There is no scientific or medical evidence to suggest that a third booster dose will help in countering the pandemic. Of course, people are entitled to their views, but there is little proof to suggest the viability of a third or booster dose. Even the World Health Organization (WHO) has said that there is no need for COVID-19 vaccine booster doses for now.

Vineeta Bal, Indian Institute of Science Education and Research, Pune, autonomous public research university established in 2006 by the Ministry of Education

There are multiple issues there:

1. It is safe to take a third shot.
2. If it is taken after a few months of the second shot, it will likely cause an increase in the antibody titres and T cell responses, though this has not been formally tested. But this is what vaccines are supposed to do.
3. From an individual perspective, this might prove beneficial.
4. Individuals who are at particularly high risk may benefit from the booster.
5. Higher antibody titres in most instances have been associated with better neutralisation capacity against the delta variant - at least for mRNA vaccines.
6. Covishield triggers robust T cell response. Whether a third shot will provide an even better response against the delta variant is unclear.
7. However, when one looks at the global picture of the pandemic when many individuals have not even received the first shot of any vaccine in many countries, the priority should be to provide them with vaccine shots. This is not just on humanitarian grounds but will in the long run help in reducing the spread of infection from the global South to the global North!
8. One thing is important to note, though no vaccine currently in use has a transmission-blocking potential. Fully vaccinated individuals can get infected, but they are unlikely to suffer from serious disease due to vaccine-induced immunity. Thus, the delta variant can still infect individuals like Poonawala, who have taken the third shot, in appropriate circumstances.

A third dose can be useful, but only if you can afford it. Maybe, the US can afford it, but can India do the same? In this country, double doses are the need of the hour. When such a large segment of the population is not inoculated, a third dose does not make sense. In any case, a third dose can be administered only 8-10 months after the second dose, and that time has not come as yet. We need to push up our speed of vaccinations.

Dr MC Mishra, Former Director, AIIMS  

Probably, a third dose or additional dose will have to be made a regular feature every few months, in the days ahead. Since the coronavirus is here to stay – viruses never go away, only immunity systems must be strengthened – it is safe to assume that some form of booster dose will always be needed, from here on. There are water-borne viruses like typhoid and cholera, among others; there are mumps, measles, and rubella, which are airborne. So, there is a need for constant protection. The only issue is the timing or the gap. The United States Food and Drug Administration (USFDA) has recommended an eight-month gap for a third dose to be given. Only a few vaccines offer lifelong protection against viruses like smallpox, mumps, and measles. So, I would recommend booster dose as a must.

Dr. Vinay Agrawal, former president of Indian Medical Association (IMA)

I am not an expert, but I would not place much faith in what a private person like Cyrus Poonawalla says. I have not seen any study that recommends a third or booster dose. If a medical body like the Indian Council of Medical Research (ICMR) or any other medical body proposes the third dose, I will be willing to go along. In my view, however, a minimum of 60 percent of the population needs to be vaccinated before we even discuss such a proposal. We are still a long way away from our goal. I understand the United Kingdom has introduced a third dose while the US has started a second dose for those who were vaccinated with Pfizer, which was a one-dose vaccine.

Gagandeep Kang, microbiologist and virologist, Professor in the Department of Gastrointestinal Sciences at the Christian Medical College, Vellore

There is no need for a booster dose now.