New Delhi: The indigenously developed Covaxin vaccine “demonstrates protective response,” against the Delta (B.1.617.2) as well as the Beta (B.1.351) variants of SARS-CoV-2, which causes Covid-19, a preprint authored by scientists at the Indian Council of Medical Research (ICMR)-National Institute of Virology (NIV) has found.
Uploaded on the platform bioRxiv Tuesday, the study, which is yet to be peer-reviewed, noted that though the scientists observed a reduction in antibody titres for the two variants, the vaccine still offered protection against infection.
Mutations of the SARS-CoV-2 virus have posed a threat to vaccine efficacy, the scientists noted, saying, “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.”
What the study found
The study compared the serum of 20 recovered Covid patients (5-20 weeks after recovery) with 17 people who were administered the second dose of Covaxin.
The serum of both these groups was exposed to the Delta and Beta variants, as well as the original variant – B1 – that was circulating when the pandemic began last year.
The study noted that Covaxin has already proven to be effective against the B.1.617.1 subgroup of the Delta variant, as well as the other variants such as the Alpha variant (previously known as Kent/UK), and the Zeta variant (Brazil).
“We observed a reduction in neutralization titers with sera of COVID-19 recovered cases and BBV152 (Covaxin) vaccines against B.1.351 and B.1.617.2 respectively,” the researchers said.
“Our study demonstrated that despite a reduction in neutralization titers with BBV152 vaccinees sera against B.1.351 and B.1.617.2, its neutralization potential is well established,” they added.
The Delta variant has produced two subgroups — B.1.617.1 and B.1.617.2, of which the latter is gaining a larger footprint.
Covaxin, which was developed by Bharat Biotech in association with the ICMR, is one of the three vaccines that have been approved for vaccination in India, the other two being Serum Institute of India’s Covishield and Sputnik V of Russia.
Also read: Gangrene, hearing loss indicate India’s Delta variant of Covid is more severe, doctors say