Covaxin's clinical efficacy at 81%

Bharat Biotech comes out with first interim analysis of phase-3 trial

Hyderabad: City-based vaccine maker Bharat Biotech on Wednesday announced the first interim analysis of its BBV152 (Covaxin). The whole virion inactivated Covid-19 vaccine candidate demonstrated an interim vaccine efficacy of 81 per cent in its Phase-3 clinical trial. The trials involved 25,800 subjects, the largest ever conducted in India, in partnership with the Indian Council of Medical Research.

Dr Krishna Ella, Chairman and Managing Director, Bharat Biotech, said: "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 not only demonstrates high clinical efficacy trend against Covid-19, but also significant immunogenicity against the rapidly emerging variants."

The first interim analysis is based on 43 cases, of which 36 cases of Covid-19 were observed in the placebo group versus seven cases observed in the BBV152 (Covaxin) group, resulting in a point estimate of vaccine efficacy of 80.6 per cent.

The interim analysis included a preliminary review of the safety database, which showed that severe, serious, and medically attended adverse events occurred at low levels and were balanced between vaccine and placebo groups. The trial's conduct and monitoring are as per Good Clinical Practice guidelines and have been outsourced to IQVIA.

The Phase-3 study enrolled 25,800 participants between 18-98 years of age, including 2,433 over the age of 60 and 4,500 with comorbidities. The primary endpoint of Phase-3 clinical trial is based on the first occurrence of PCR-confirmed symptomatic (mild, moderate, or severe) Covid-19 with onset at least 14 days after the second study vaccination in serologically negative (to SARS-CoV-2) adult participants at baseline.

BBV152 contains a whole virion inactivated SARS-CoV-2 vaccine, which is produced in vero cells. It is stable at 2 to 8°C (refrigerated) and is shipped in a ready-to-use liquid formulation that permits distribution using existing vaccine supply chain channels. BBV152 has a 28-day open vial policy as a unique product characteristic, thus reducing vaccine wastage by approximately 10-30 per cent.