Govt studying BCG vaccine use as Covid booster shot after Covaxin
NEW DELHI: The national Covid taskforce is reviewing a proposal to evaluate the efficacy of the Bacillus Calmette Guerin (BCG) vaccine as an immune booster with Covid-19 vaccine Covaxin, with a plan to possibly carry out an open label randomised controlled trial to determine if it reduced incidence or severity of the viral disease.
The trial was discussed during a meeting, according to minutes seen by HT, and is based on past signs that BCG vaccine may offer some benefit in fighting of Covid-19. The new proposal concerns with using it as a booster.
“The proposal was floated in one of the task force meetings this year. There have been studlosis ies that found BCG showing some promise against Covid-19 among elderly. The fresh proposal was meant to see how well it works as a booster in those who have taken Covaxin as their primary dose,” said one of the members of the task force, requesting anonymity.
BCG vaccine primarily provides protection against tubercuand has been administered to newborns as part of Centre’s National Immunization Programme for the least 50 years. The dose is a live attenuated vaccine strain of mycobacterium bovis, which is meant to protect against mycobacterial infections such as tuberculosis and leprosy. The vaccine is also known to protect against heterologous — or over one — infection of the pathogen it is designed against.
With BCG there have been two trials in India as well— one is to evaluate efficacy of BCG in reducing the incidence and severity of Covid-19 in the highrisk population. The other study has been to evaluate the effectiveness of BCG vaccine in reducing morbidity and mortality in elderly individuals in Covid-19 hotspots in the country.
The Indian Council of Medical Research ( ICMR) has been spearheading the studies.
In September last year, ICMR also published a paper based on results of the second study (on elderly population) in the International Journal of Infectious Diseases which showed the BCG could improve the response to vaccines directed against viral infections most likely by protecting against unrelated infections. This, they hypothesised, was because it seemed to play a role in stimulating a kind of immune cell called dendritic cells.
“…BCG vaccination was associated with enhanced DC subsets and IL-28A/IL-29 in elderly individuals, suggesting its ability to induce non- specific innate immune responses,” read the ICMR paper.