Vaccination / May need COVID-19 vaccines' booster shot to fight emerging variants: AIIMS chief

New Delhi: All India Institute of Medical Sciences (AIIMS) director Dr Randeep Guleria has said India might have to adopt a booster dose with second-generation Covid-19 vaccines as the Delta variant of the coronavirus has swept across the world and driven up infections in several countries.

"It seems that we probably need the booster dose of vaccines as with the passage of time the immunity tends to fall," Dr Guleria said in an interview with ANI. "There is waning immunity. We would like to have a booster dose that will cover for various emerging variants," Guleria said adding that the booster dose will be a second-generation vaccine.

"We will have second-generation vaccines which would be better in terms of the immunity they give, covering of the new variants and a having a better overall efficacy," Guleria said.

The Delta variant, which first emerged in India and is spreading around the globe, has infected those already fully vaccinated against Covid-19. The spread of the Delta variant has forced some countries to step up their vaccination campaigns and bring back curbs on businesses, activity and travel.

Guleria said that trials of booster shots are already on. "You will probably need a booster dose till the end of this year. But that's only once the population is vaccinated, then the next step will be to administer a booster dose," he added.

In India, breakthrough infections or infections after one or two doses of vaccines have also been reported from several parts of the country. The government said earlier this month it will take time to come to a concrete conclusion about the requirement of booster dose while Bharat Biotech is carrying out the trial of its booster shot, which will be the third shot after the two-dose vaccination.

"Booster dose is in the stage of scientific ideation," Dr Balram Bhargava, director-general, the Indian Council of Medical Research, said last month.

Bharat Biotech, the makers of Covaxin, got the Drug Controller General of India's nod in April to conduct trials for a third shot, which will be administered as a booster dose. According to reports, the trial is ongoing and the result of the first trial result is likely to be out next and the final one is expected by November. The booster shot might become a yearly thing to keep the immune system to the optimum level.

In the US, Pfizer and BioNTech have said that they are developing a Covid-19 booster shot intended to target the Delta variant as concerns rise about the highly transmissible strain.

The companies said they are “remaining vigilant” and developing an updated version of the vaccine even though they believe the third shot of their current two-dose mRNA vaccine has the potential to preserve the “highest levels” of protection against all currently known variants, including Delta.