Bharat Biotech's Covaxin is effective against the Delta and Delta plus variant, a study by the Indian Council of Medical Research and National Institute of Virology has said.
The study released on Monday showed that Covaxin provides 65.2 per cent protection against the Delta variant which was first detected in India. The Delta variant which has spread to 99 countries is a variant of concern and was also responsible for the second wave in India.
The Delta variant has also been identified as the leading cause of breakthrough infections globally among vaccinated individuals, the study said. The study said that a minor reduction in the neutralising antibody titer in Covid-19 recovered cases and full BBV152 vaccinated and post immunized infected cases was observed but the vaccine was found to be effective against the Delta, Delta AY.1 and B.1.617.3 variants.
The study published as a pre-print on bioRxiv said that Sera of vaccines among Covid naïve recovered cases with full vaccination and breakthrough cases demonstrated 1.3, 2.5 and 1.9-fold reduction against Delta variant in comparison to B.1 variant respectively.
This demonstrates the possible role of memory cells in immune-boosting with post-infection or infection after immunization.
The comparative analysis of all the groups revealed that the B.1.617.3 seems to be less susceptible to neutralization followed by Delta AY.1 and Delta variants compared to B.1,” the study said.
Two shots of AstraZeneca which is the same as the Covishield vaccine were 67 per cent effective against the Delta variant according to a study published in the New England Journal of Medicine.