Covaxin booster effective against Omicron, Delta

New Delhi: Hyderabad-based biotechnology firm Bharat Biotech on Wednesday said a booster shot of its Covid-19 vaccine Covaxin will neutralise both Omicron and Delta variants of Covid-19.

Booster dose of Covaxin generated robust neutralising antibody responses against both Omicron and Delta variants of SARS-CoV-2, Bharat Biotech said. The study was conducted at the Emory Vaccine Center in Atlanta based on blood serum collected from 13 individuals, 28 days after their booster shot. It was sponsored by Bharat Biotech's partner Ocugen Inc.

"The neutralisation activity of Covaxin-boosted sera was comparable to what has been observed in mRNA vaccine-boosted sera against the Omicron variant," Bharat Biotech said in a statement. "More than 90% of all individuals boosted with Covaxin showed neutralising antibodies."

Bharat Biotech had earlier said trials have indicated that its vaccine Covaxin is safe for booster dosage against Covid-19. The Hyderabad-based company had announced the results on the safety and immunogenicity of COVAXIN (BBV152).

The analysis showed, six months after a two-dose Covaxin (BBV152) vaccination series cell-mediated immunity and neutralising antibodies to both homologous (D614G) and heterologous strains (Alpha, Beta, Delta, and Delta plus) persisted above baseline, although the magnitude of the responses had declined, the company said.

Furthermore, neutralising antibodies against homologous and heterologous SARS-CoV-2 variants increased from 19 to 265 folds after a third vaccination, it said.

Booster BBV152 vaccination is safe and may be necessary to ensure persistent immunity to prevent breakthrough infections, it said. "These trial results provide a strong foundation towards our goal to provide Covaxin as a booster dose. Our goal of developing a global vaccine against Covid-19 has been achieved with Covaxin indicated for adults, children, two dose primary and booster doses. This enables use of the vaccine as a universal vaccine," Bharat Biotech Chairman and Managing Director Krishna Ella said.