India’s Covaxin® 81 percent effective against COVID-19

Bharat Biotech has announced that Covaxin® (BBV152), its COVID-19 vaccine developed and authorised for emergency use in India, was shown to be approximately 81 percent effective at preventing COVID-19 in an interim analysis.

The analysis assessed data from a trial involving 25,800 subjects between 18-98 years of age, the largest ever conducted in India. The Phase III trial includes 2,433 people over the age of 60 and 4,500 who have comorbidities.

The primary endpoint of 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 adult participants at baseline.

The first interim analysis includes 43 cases, of which 36 cases were observed in the placebo group versus seven cases in the Covaxin group. This results in a point estimate of vaccine efficacy of 80.6 percent.

The interim analysis also included a preliminary review of the safety database, which indicates that severe, serious and medically attended adverse events occurred at low levels and were balanced between Covaxin and placebo groups.

Aside from the clinical data, a preclinical study by the National Institute of Virology (NIV) indicates that Covaxin-induced antibodies can neutralise the UK variant strains and other heterologous strains, which has been published in preprint on bioRxiv.

“Today is an important milestone in vaccine discovery, for science and our fight against coronavirus. With today’s results from our Phase III clinical trials, we have now reported data on our COVID-19 vaccine from Phase I, II and III 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 Dr Krishna Ella, Chairman & Managing Director, Bharat Biotech.

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

Bharat Biotech expects to share further details of the trial results as additional data become available. An additional interim analysis is planned for 87 cases and the final analysis is planned for 130 cases. All data from the second interim and final analyses will be shared via prepublication servers, as well as submitted to a peer-reviewed journal for publication.

Prashant Khadayate, Pharma Analyst at GlobalData, stated in response to the news: “Interim efficacy data will improve the market penetration of Covaxin both in India and other countries.” According to Khadayate, so far, Covaxin has accounted for just 12 percent of the >15 million COVID-19 vaccine doses delivered in India, with the other 88 percent “belong to Covishield from Serum Institute of India/ AstraZeneca”, which was shown to be 62 percent effective in interim analyses.