NEW DELHI: Covaxin offers significant protection against both beta and delta variants of the SARS-CoV-2 virus, according to a new study. Both these variants of the coronavirus have emerged as a global health concern with Delta being the most dominant strain in various countries and associated with very high transmissibility, severe disease and also potential immune escape properties.
The massive Covid second wave in India, scientists have established, was largely driven by a delta variant, first originated in Maharashtra before it spread out across the country. In the latest study published in the Journal of Travel Medicine, researchers associated with ICMR and Bharat Biotech examined blood samples from 20 people who had recovered from Covid as well as 17 of those who received Covaxin.
The researchers assessed the ability of these samples to neutralise the beta and delta variants and found that the vaccine conferred significant protection against both variants. The study said that the potential immune escape properties of beta and delta variants has been a serious concern for the Covid vaccination programme, since it has shown reduced neutralisation to several vaccines.
Previously, the Covaxin neutralisation potential was already studied by the team with the alpha, zeta and kappa variants and the vaccine was found to be effective against these variants. As part of the scientific exercise, the researchers assessed the neutralisation of blood samples from 20 Covid recovered people between 5 to 20 weeks after infection. In addition, blood samples from 17 vaccine recipients collected 28 days after two doses of Covaxin were also assessed against beta and delta variants.
Among the recovered cases, three were infected with kappa lineage, while 17 were infected with delta variant. The team carried out the plaque reduction neutralisation test, which is used to quantify the concentration of neutralising antibodies for a pathogen. “Our study demonstrated that despite a reduction in neutralization titers with BBV152 (Covaxin) vaccinees’ sera against beta and delta variants, its neutralisation potential is well established,” the authors said.
Efficacy against other variants studied earlier
Apart from the two variants, the Covaxin neutralisation potential was already studied by the team with alpha, zeta and kappa variants. The indigenous vaccine was found to be effective against these variants as well.