Should you get the fourth vax dose? Read all about Covid-19 booster dose

Answered: Who needs a booster shot? Which vaccine one should go for? What should those who received Sputnik V do?

ByChetana Belagere

Published Dec 23, 2022 | 7:36 PMUpdatedDec 25, 2022 | 9:07 AM

covid booster dose

The central government mooting precautionary anti-Covid vaccine doses for citizens has left several people confused: Whether everyone should get booster doses, how many doses one should receive, which vaccine if the previous one is not available, etc.

South First spoke to experts to clear the doubts.

Several states, including Karnataka, have been stressing the need for getting booster doses to inoculate people against SARS-CoV-2, the Covid-causing virus.

Speaking to South First, Dr MK Sudarshan, the Head of Karnataka’s Covid-19 Technical Advisory Committee, said that only 25 percent — one out of five — have been administered the booster dose in the state.

“BF.7 is a highly transmissible variant of the virus and we are now beginning to take precautions and preventive measures. It is strongly recommended and advised that the elderly, those with comorbidity in particular, and those who have not received the booster shot, should voluntarily get vaccinated,” he said.

The government of Karnataka would arrange special vaccination camps, he added.

Incremental benefit

However, while discussing studies on the benefits of booster vaccinations, India’s top virologist, Dr Gagandeep Kang of Christian Medical College in Vellore, Tamil Nadu, explained that they would have an incremental benefit in anyone, at least for a while.

“All vaccines available in India are fine,” she said. “But in the order of immune response, protein-based vaccines are good, and then adenovirus vectored and inactivated vaccines.”

Two doses of any vaccine would protect the recipient against severe infection/death. “We have no data on whether the effectiveness of Indian vaccines has waned over time, but from the rest of the world, the effect of booster on the elderly population is clear,” Dr Kang told South First.

Watch: Absolutely no need to panic, says India’s top virologist

Who should get a booster dose?

Dr Kang explained that the elderly would need an additional dose as a precautionary measure. However, she added that precautionary vaccines might not be that effective in younger, healthier people.

India mooting booster dose for all without having any data or comparative analysis has left the virologist baffled. She said she was unsure about the need for and the potential impact of rolling out a booster vaccination drive as part of a public health programme.

Dr Rajeev Jayadevan, Co-Chairman, National IMA COVID Task Force and former president of IMA, concurred.

He said those aged below 60 need not opt for boosters due to two reasons: One, most people in that segment have hybrid immunity — all of them have been infected at least once, if not multiple times.

“Since 75 percent of natural Covid infections are asymptomatic, the vast majority of the younger population have already been infected. So this means that people have had at least three immune exposures,” he said.

“If you have hybrid immunity, there is no need for a young adult to get another dose,” he opined.

The second reason Dr Jayadevan pointed out was the lack of published data on patients’ actual clinical outcomes of booster doses administered in India. “All we have is lab data which does not correlate with the clinical outcomes,” he added.

“Until we have a comprehensive study data from India — saying those who had received ‘X’ vaccine and ‘Y’ booster were better or worse than those administered with ‘P’ vaccine and ‘Q’ booster — it would be futile to talk about what people should be doing,” he explained.

However, those above 60-65 years of age could be considered vulnerable. “We know the complications in this age group suffered even from Omicron infection was remarkably high,” Dr Jayadevan said.

He recommended booster doses to the elderly and those in the high-risk category such as nurses, social workers, vendors, and postal delivery personnel.

Dr Jayadevan insisted that readers should know that vaccines do not protect significantly against infections. “People should not be under the impression that they will not be infected if they get the vaccine,” he said.

WATCH: Message from Covid experts is clear: Don’t panic, take precautions

Different scenarios: Who and which vaccine

While doctors advised booster doses for those aged above 60, several readers of South First asked if a vaccine cocktail is recommended: If one had been administered Covishield, could s/he opt for Covaxin as the booster dose and vice-versa.

Scenario 1: Covishield as primary dose

Experts differed. Dr Chandrakant Lahariya, a Delhi-based vaccine and public health policy expert, advised the same vaccine as a booster.

“Follow the Indian guidelines and take Covishield as the booster, if both her/his primary doses have been the same vaccine,” he told South First.

However, Dr Jayadevan said an individual could opt for either of the vaccines. “Both will protect against the severity of the disease.”

Meanwhile, a senior doctor in Karnataka’s Technical Advisory Committee recommended Biological E’s Corbevax also as a booster dose for all adults above 18 years if the person has taken a primary dose of Covishield.

“This has been approved by the Indian government in August 2022 and is available as an option on the CoWIN platform too,” he pointed out.

Corbevax booster dose could be administered after six months or 26 weeks after the second dose.

Scenario 2: Two doses of Covaxin. What next?

Similar to two doses of Covishield, people who have taken Covaxin may go for the same vaccine as their booster shot. They can even opt for Covishield or Corbevax.

Scenario 3: Two doses of Sputnik V

Those who have received Russia-developed Sputnik V have been facing several issues, ranging from the non-availability of the vaccine to several countries denying them visas.

Experts South First spoke to, clarified that since Sputnik is a viral vector vaccine, it would be considered equivalent to Covishield.

Dr Jayadevan explained: “If you were vaccinated with two doses of Sputnik, it is considered equivalent to taking Covishield. The reason is both vaccines were developed using the same technology. Those who were administered Sputnik will be considered to have received the same protection as those who were administered Covishield. They can take either Covishield or Covaxin.”

Meanwhile, Dr Swati Rajagopal, Consultant, Infectious Disease and Travel Medicine, Aster CMI Hospital in Bengaluru, agreed that Sputnik V recipients were experiencing a host of issues.

“They are visiting medical facilities after an increase in Covid cases across the world. The health ministry has confirmed that those who were administered Sputnik V may choose Covaxin or Covishield,” she explained.

Scenario 4: Should I get a fourth dose?

Experts ruled out the need for the fourth dose of Covishield. Dr Jayadevan said there was no data on the need for a second booster (fourth shot) in India. “Covishield is not an mRNA vaccine,” he pointed out.

“mRNA is like putting a key and turning on the engine, whereas receiving Covishield is like putting a whole organism inside you. They work differently. The mRNA vaccine is short-lived, and that is why you need to take it every few months. Whatever you see in literature and news about multiple vaccine doses are all mRNA vaccines,” he said.

Dr Lahariya also said ‘no’ to a fourth dose.

Interestingly, some doctors, requesting anonymity, told South First that they had received multiple booster doses.