Time for govt to act is now: Virologists on booster dose

MUMBAI: To stay ahead of the Omicron threat, health experts want the government to urgently decide on booster shots, especially for the immunocompromised and elderly. While India has detected 38 Omicron cases so far, it is predicted to replace Delta as the dominant variant in the months to come.

Leading virologists argue that even as evidence is collected on need for boosters, the government must prepare to roll it out for the susceptible population. They also said that full vaccination must be accelerated using all means.

Booster dose makes a lot of sense and the time for the government to "act is now", Vellore-based virologist Dr T Jacob John told TOI. "Why are we being stingy about a dose of vaccine?" he said. "Two shots are for priming the immune system, and that priming effect is likely to wane in six months to a year," he said, adding a booster will increase the immune response exponentially.

Echoing Dr John, eminent virologist Dr Shahid Jameel, also the former head of the advisory group to the Indian SARS-COV-2 Genomics Consortia (Insacog), said that immunocompromised must get boosters on priority. "If they have got two doses, they must get a third dose," he said. But, boosti-ng somebody with a third dose of the same vaccine they have been immunised with previously may not do much good, he said.

Upto 90% of the vaccine rollout in India has been with Covishield. "A third dose of Covishield may not do much good as the background vector immunity will not allow the virus to infect very well and raise the spike immunity," he said. In his opinion, mRNA vaccines (developed by Moderna and Pfizer), are good booster candidates.

"ZyCov D can be made available as a booster. Even Covaxin can be used as a booster for people who got Covishield and vice Versa," said Dr Jameel.