A booster shot of indigenously developed Covid-19 vaccine Covaxin administered six months after getting two doses of the vaccine, has been found to successfully neutralise both the Omicron and Delta variants of SARS-CoV-2, a study conducted at Emory University has shown. Bharat Biotech said the study conducted using a live virus neutralisation assay showed the booster dose generated robust neutralising antibody responses against both Omicron (B.1.529) and Delta (B.1.617.2).
“100% of test serum samples showed neutralisation of the Delta variant and more than 90% of serum samples showed neutralisation of the Omicron variant,” Bharat Biotech said, pointing out that these data add to the body of evidence that the broad-spectrum mechanism of action of a whole virus inactivated Covid-19 vaccine like Covaxin is a viable option in this continuously evolving pandemic.
Bharat Biotech said the neutralisation activity of Covaxin-boosted sera was comparable to what has been observed in mRNA vaccine-boosted sera against the Omicron variant with more than 90% of all individuals boosted with Covaxin showing neutralising antibodies.
“As the dominant Covid-19 variant throughout the world, Omicron poses a serious public health concern,” said Mehul Suthar, assistant professor, Emory Vaccine Center, who led the laboratory analysis.
“Data from this preliminary analysis show individuals receiving a booster dose of Covaxin have a significant immune response to both the Omicron and Delta variants. These findings suggest that a booster dose has the potential to reduce disease severity and hospitalizations,” Suthar added.
The study will be published on the pre-print server, medRXiv, shortly.
Bharat Biotech Chairman and Managing Director Dr Krishna Ella said the company was in a continuous state of innovation and product development for Covaxin.
“The positive neutralisation responses against the Omicron and Delta variants validate our hypothesis of a multi-epitope vaccine generating both humoral and cell-mediated immune responses. Our goals of developing a global vaccine against Covid-19 have been achieved with the use of Covaxin as a universal vaccine for adults and children,” he added.