Bharat Biotech's Covaxin has an efficacy of 77.8 percent against COVID-19, according to reports quoting sources at the Drug Controller General of India's (DCGI) Subject Expert Committee. The final phase 3 results of the clinical trial were submitted to the DCGI over the weekend.

Phase 3 trials were conducted on 25,800 participants across India between December 2020 and March 2021.

Earlier, Bharat Biotech had said that the data would be submitted to peer-reviewed journals for publication after it had been reviewed by DCGI.

Bharat Biotech has sought Emergency Use Listing (EUL) from the World Health Organisation (WHO), and the company is said to have submitted nearly all the data sought.

The USFDA had rejected Bharat Biotech's petition for emergency use approval and had asked the company to apply for full approval via regular channels.

Covaxin has been jointly produced by Bharat Biotech, Indian Council of Medical Research and National Institute of Virology.

The Phase 3 study was conducted on 25,800 participants between the ages of 18 and 98, of which 10 percent were over the age of 60.

On 21 April, Bharat Biotech had announced that their COVID vaccine, Covaxin, was found to have an efficacy of 78 percent in a second interim trial result.

The first Interim results of the phase 3 trials published back in March had found the vaccine to be 81 percent effective in preventing COVID.

In January, Covaxin was given 'Emergency Approval Under Clinical Trial Mode' in India, along with Covishield, a vaccine made by Serum Institute of India.

Once the interim results of phase 3 were announced, the 'clinical trial mode' came to an end.

Bharat Biotech has consistently faced criticism for not sharing the full phase 3 data in public, something they now say they will do in peer reviewed journals. They've also said that once they release full data, they will be apply for full approval of their vaccine.

An ongoing study being conducted by the National institute of Virology-Indian Council of Medical Research (ICMR) and Bharat Biotech found that Covaxin provides protection against the Delta (B.1.617.2) and the Beta (B.1.351) variants of the COVID-19 virus.

The small study compared the blood samples of 20 participants who recovered from COVID with that of 17 participants who were vaccinated with Covaxin, to check their immune response to the Delta and Beta variants of COVID-19.

The results found that Covaxin recipients had a 3. 0 and 2.7 fold reduction in neutralisation titers (Antibody production) against the Beta and Delta variants respectively, as compared to the 3.3 fold and 4.6 fold reduction in neutralisation titers witnessed in COVID recovered participants.

What this means is that although the vaccine produced lesser antibodies against the variants as compared to the original strain, it is still higher than those produced by COVID recovered patients.