Bharat Biotech says Covaxin efficacy 81%

Covaxin, the first coronavirus vaccine developed in India, has an efficacy rate of 81%, its maker Bharat Biotech said while citing preliminary results from its Phase 3 clinical trials, an announcement that is likely to come as a shot in the arm for India’s vaccination drive.

The vaccine was approved for an emergency roll-out on January 16 before it was established to be effective in preventing Covid-19, but experts as well as authorities pointed to Phase 1 and 2 trials that showed that Covaxin was safe and produced an adequate immune response.

“Today is an important milestone in vaccine discovery, for science and our fight against coronavirus. With today’s results from our Phase 3 clinical trials, we have now reported data on our Covid-19 vaccine from Phase 1, 2, and 3 trials involving around 27,000 participants. Covaxin demonstrates high clinical efficacy trend against Covid-19 but also significant immunogenicity against the rapidly emerging variants,” said Krishna Ella, chairman and managing director, Bharat Biotech.

The results revealed on Wednesday — detailed data is yet to be released or peer-reviewed — are based on an interim analysis when 43 infections took place among the 25,800 people who were part of the trials. Of these, 36 were among those given a placebo, while seven got the vaccine, translating to an efficacy rate of 80.6%, the company said.

PM Narendra Modi and Union health minister Harsh Vardhan both took Covaxin to build faith in the indigenous vaccine, which has met with severe hesitancy, particularly among health care workers, for want of the efficacy data. Disaggregated data from Delhi, for example, showed in January that turnout at locations administering Covaxin was as low as 25%, while it was 75% for those using Covishield – the domestically produced version of the Oxford-AstraZeneca vaccine.

As on Wednesday, 16.3 million doses of the two vaccines have been administered to people across the country.

Covaxin uses an inactivated virus paired with an adjuvant – a chemical that boosts immune response.

“Covaxin has been literally developed from scratch in India; the only thing that is foreign about the vaccine is the virus strain that came from China through a medical student, and that was isolated at ICMR-NIV) in Pune on March 9. The virus isolate was transferred to Bharat Biotech around the end of April,” said Dr Balram Bhargava, director general, ICMR.