The vaccines vastly used in India – Oxford/AstraZeneca vaccine dubbed as Covishield locally and Bharat Biotech/Indian Council of Medical Research’s Covaxin vaccine – produce fewer antibodies against the highly transmissible Indian variant (B.1.617).
The B.1.617 strain which was first detected in Maharashtra has become a dominant strain in India since April. Other prominent variants are B.1.1.7 (UK variant), the B.1.351 (South Africa variant), the P2 (Brazil variant)
Scientists at National Institute of Virology (NIV), Pune tested the B.1.617 mutations, on antibodies that were extracted from the blood serum of those with two doses of Covaxin, they found roughly 55% lesser antibodies than the antibodies generated against B.1.1.7 variant.
In the case of Covishield, the antibody levels for B.1.617 was 21.9 percent while it was 42.92 percent for the B.1.1.7 variant.
Some scientists say that a two-fold reduction isn’t serious at all and was on expected lines. “A ten fold or greater level of reduction may be important but then again different labs have varying approaches to conducting such tests,” Rakesh Mishra, former Director, Centre for Cellular and Molecular Biology (CCMB) said.
Even with the decline in efficacy, several researchers continue to maintain that the drop doesn’t diminish the fact that the vaccines continued to be a potent tool against Covid-19.