HYDERABAD: Indigenously developed Covid-19 vaccine Covaxin protects against the deadly Beta (B.1.351) and Delta (B.1.617.2) variants, more commonly referred to as the South African and Indian variants, a study has found.
The study, conducted to evaluate the neutralisation potential of the Covaxin, found a 3-fold and 2.7-fold reduction in neutralisation titres (concentration of neutralising antibodies) against Beta and Delta variants.
On the other hand, the study found that the reduction in neutralising titres using sera of Covid-19 recovered cases was 3.3-fold and 4.6-fold against Beta and Delta variants.
The researchers concluded that with a lower reduction in neutralisation titre in those vaccinated with Covaxin as compared to naturally infected individuals, the whole-virion inactivated vaccine demonstrated protective response against the two variants of concern.
“Our study demonstrated that despite a reduction in neutralization titers with BBV152 vaccines sera against B.1.351 and B.1.617.2, its neutralization potential is well established.
Lastly, the broad epitope coverage of an inactivated vaccine (BBV152) decreases the magnitude of reduced neutralization against emerging variants,” the researchers said.
The study, which was uploaded on bioRxiv that carries preprints of research papers before they are peer-reviewed, was conducted by researchers from the National Institute of Virology (NIV), Indian Council of Medical Research (ICMR) and Bharat Biotech.
The study was conducted by collecting the sera of 20 people after 5-20 weeks of their recovery from Covid-19 infection.
This included 17 people that were infected with B.1 and three people infected with B.1.617.1 lineage virus.
The researchers also collected sera of 17 people who were vaccinated with Covaxin after 28 days of their getting both the jabs.
The study looked at the neutralisation potential of the vaccine against Beta and Delta variants as compared to the prototype B.1 (D614G).
With the increasing threat of the SARS-CoV-2 variants, it is imperative to assess the efficacy of the currently available vaccines against these variants, the researchers said.