India Calls It 'Precautionary', Not Booster Dose – Experts Explain Why

"In medical sciences, there is no such term called the precaution dose," said Dr Subhash Salunkhe.

If all the other countries using a third shot prefer the term 'booster', why exactly is India using a different one? Image used for representational purposes.

(Photo: Altered by The Quint)

When Prime Minister Narendra Modi announced a third shot of coronavirus vaccine for healthcare workers and those above 60 years of age, he used a term that was not previously heard or used in the context.

Addressing the nation amid a rise in Omicron cases, he said that the two at-risk categories of people will be eligible for a "precautionary" dose – not a booster – starting 10 January.

If all the other countries using a third shot prefer the term 'booster', why exactly is India using a different one?

It is more than just a substitute word, and there is more to it than what meets the eye, multiple experts told The Quint.

Dr Chandrakant Lahariya, an epidemiologist and health systems experts, explained that while only the government can clarify the term, India is likely to use the same vaccine for an additional dose – and this may not really act as a booster.

"There is an informal understanding that there is not enough clarity to administer booster shots. If and when there is evidence to give booster shot, the vaccine should be of another platform – one that is different from the first two shots. In India, there is no booster shot available, and the government is more likely to use the same vaccine for the additional shot. Therefore, it does not fit the criteria of a booster shot. Maybe, the government has called it precautionary for the same reason."

Dr Chandrakant Lahariya, Epidemiologist

There is limited evidence for need for a booster shot in India and one does not know whether India needs to administer booster to all adults, he added.

Dr Rakesh Mishra, former director of the Center for Cellular and Molecular Biology, too, echoed Dr Lahariya. He told The Quint that at present it may even be more strategically correct to call these additional doses 'precautionary' doses as there is no data available on the efficacy of the third dose.

"I think at the moment it is more reasonable and strategically correct to call it precautionary shot, since there is not much data available. Booster shot is something that is more specific, and more studied on. Therefore, it is more accurate to call it precautionary dose."

"It is a precaution shot for those who are at risk. Since, we do not know enough, it cannot be called a booster," Dr Lahariya added.

'Govt Must Clarify the Term'

Public Health Expert and National Task Force Member Dr Subhash Salunkhe said that the government should provide clarity as there is no precedence of a term like this being used before.

"I personally feel in medical sciences, there is no such term called the precaution dose. There is a primary dose, a booster dose, and even a second booster. But I have never heard of a precaution dose. I want to leave it to the wisdom of those who designed it," he told The Quint.

"But I feel that the government should really explain why this is so, instead of giving room to speculation. It needs to be explained why they have chosen this name.This could save a lot of confusion – to people and the scientific community," Salunkhe added.

Another leading virologist, who did not want to be named, added that the government may be hesitating to use the term booster – as India has still not procured Moderna and Pfizer vaccines, both of which are widely being used as booster shots across the world. They added:

"In almost all countries that have started giving booster, Pfizer or Moderna is being used. India does not even have access to these yet. Take for example AstraZeneca's Covishield. In UK, those who received AstraZeneca vaccine for first two doses, got Pfizer as the booster. Multiple studies were cited before taking the call. In India, we do not have Pfizer, and we do not know whether another dose of Covishield is even going to be effective. So this is why the government may be hesitating to use the term booster."

How Effective Is Same Dose for Third Shot?

If India chooses to administer the same vaccine for the 'precautionary' dose (also since there are no options left), how effective will these be as boosters?

We do not know enough, say experts.

An expert panel of India's central drug authority, on 10 December asked for more data as it considered Serum Institute's application for the approval of Covishield as a third dose of vaccine for COVID-19. Meanwhile, trials for using Bharat Biotech's Covaxin as third dose are also underway. But data for neither is available in the public domain.

Citing a study carried out by Oxford University, AstraZeneca on 23 December said that a three-dose course of its COVID-19 vaccine is effective against the new coronavirus variant Omicron.

The antibodies generated after the booster shot were higher when compared to the levels generated in people who had naturally recovered from COVID-19, the company said, adding that it is, however, working with its collaborator Oxford University to create a tailor-made vaccine for Omicron. But this study is yet to be peer-reviewed.

Meanwhile, a Lancet study earlier this month revealed that a booster dose of as many as six COVID-19 vaccines is safe and elicits strong immune responses in fully vaccinated people.

The study looked at safety, immune response, and side effects of seven vaccines as boosters – Oxford-AstraZeneca, Pfizer-BioNTech, Novavax, Janssen, Moderna, Valneva, and Curevac. It was noted that booster vaccines increased the immune response when administered after two doses of Oxford-AstraZeneca shots.

"Giving a third shot of any vaccine will increase the antibodies. This is scientifically known. But increase in anti-bodies does not mean that it offers real-life protection. Neutralising anti-bodies in a lab setting is very different from real life. In real life, context comes into play. Therefore, it is important to study it," said Dr Lahariya.

Dr Salunkhe feels that India does not have the time to study the efficacy right now – as the benefit outweighs the risks.

"For those who have taken Covaxin or Covishield, they can take a third dose of the same. I do not know how effective it will be – no studies have been done. But it cannot do any harm to people. So instead of giving room for speculation, government should start using it and protecting people.The extent of benefit will be clear only after further studies. But we do not have the time to wait," he said.