NEW DELHI, Mar 3: India-made COVID-19 vaccine Covaxin has demonstrated an interim clinical efficacy of 81% in its Phase 3 clinical trial, vaccine maker Bharat Biotech said.
Covaxin has demonstrated high clinical efficacy trend against COVID-19 as well as significant immunogenicity against the rapidly emerging variants, CMD Krishna Ella said.
A statement from Bharat Biotech, which developed the vaccine in collaboration with Indian Council of Medical Research (ICMR), said 25,800 participants between 18-98 years of age were enrolled for the Phase 3 study. It included 2,433 over the age of 60 and 4,500 with comorbidities.
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 Covaxin group, resulting in a point estimate of vaccine efficacy of 80.6%.
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.
A release said analysis from the National Institute of Virology indicates that vaccine-induced antibodies can neutralize the UK variant strains and other heterologous strains.
Noting that the vaccine demonstrated the interim efficacy in preventing COVID-19 in those without prior infection after the second dose, the company said the 25,800 participants received a vaccine or placebo in a 1:1 ratio. Clinical trials will continue through to final analysis at 130 confirmed cases in order to gather further data and to evaluate the efficacy of Covaxin in additional secondary study endpoints.
Ella 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 (BBV152) contains a whole virion inactivated SARS-CoV-2 vaccine, which is produced in Vero cells. It is based on an established manufacturing platform with a better safety profile when compared to other vaccine platforms, the release said.
The release said 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 pre-publication servers as well as submitted to a peer-reviewed journal for publication.
(Manas Dasgupta)