Covaxin booster safe, fights SARS-CoV-2 sub-variants: Nature

Hyderabad: A third dose of Bharat Biotech’s Covid-19 vaccine, Covaxin, is safe and increases the concentration of neutralising antibodies against the ancestral vaccinated individuals, according to the results of a study published in reputed scientific journal Nature.

The results indicate that a booster dose of Covaxin (BBV152) is safe and necessary to ensure persistent immunity to minimise breakthrough infections of Covid-19 due to newly emerging variants, it said.

“Administration of a third dose of BBV152 increased neutralisation titers against both homologous (D614G) and heterologous strains (Alpha, Beta, Delta, Delta Plus and Omicron) with a slight increase in B cell memory responses. Thus, seroconversion rate remain high in boosted recipients compared to non-booster, even after six months, post third dose against variants,” the study published in Nature said.

“No serious adverse events were observed, except pain at the injection site, itching and redness,” it added.

As per the results published, researchers reported the persistence of humoral and cell mediated immunity up to 12 months of vaccination, despite a decline in the magnitude of antibody titers post six months of the second dose.

The study was conducted by researchers from Bharat Biotech, Indian Council of Medical Research-National Institute of Virology as well as the various hospitals where the trials were conducted. Bharat Biotech had earlier reported that the inactivated, whole virus vaccine had an interim efficacy of 93% against severe Covid-19 and 65% against the Delta variant.