To boost or not to boost is the question that confronts governments, as reports from different parts of the world suggest the possibility of waning immunity in people despite taking the two doses of the vaccine.

Recently, the US approved a third dose in people with compromised immunity, even as Israel proceeds with giving its people booster doses. This is even as experts with the World Health Organization advise against boosters, as data do not show a need for it and because the world is witnessing a lop-sided distribution of vaccines. Nevertheless, the US is also set to begin its booster campaign in late-September.

Making sense of the multiple messages on booster doses, waning immunity and breakthrough infections, Dr Trupti Gilada is not for the one-size-fits-all approach. “There should not be the same yardstick to measure everyone,” she says, advocating a more tailored strategy of giving a third dose (not booster) to those who are immuno-compromised. For example, people undergoing cancer treatment, organ replacement, those with chronic kidney disease and dialysis, she explains, of conditions that are defined as being moderate to severe. Dr Gilada is an infectious diseases specialist with Mumbai’s Masina Hospital, an institution also famed for having treated patients during the Spanish flu 100 years ago.

Compromised immunity

People with compromised immunity need to be prioritised and given a third dose as part of the primary series because their immunity response may not have built up in the first place or was waning, she explains. India needs to create its own data on these groups and procurement of vaccine supplies for them, she added.

On breakthrough infections, where people get infected despite the two does of the vaccine, she said the clear benefit from the vaccine is that it protects from severe disease, hospitalisation and death. And information from other countries on breakthroughs reveal that over 90 per cent of the hospitalisations are in the unvaccinated population, she said. “The vaccine benefit is starkly glaring in the face,” she adds.

Further, she says more than the antibodies, the clear indicator that vaccines work is reflected in the hospitals. There are not as many hospitalisations, she says, drawing comparisons with the surge in admissions during the first and second wave of infections. Responding to whether the elderly need to be given a third dose, since they are known to show a weaker immune response, she said, this too needed more data to be generated before a decision is made.