Interim analysis of phase-3 trials of COVAXIN shows 78% clinical efficacy, claims Bharat Biotech

Bharat Biotech and ICMR announced interim results from the Phase three trials of COVAXIN. According to them, COVAXIN has shown an overall estimated clinical efficacy of 78 percent against mild, moderate, and severe COVID-19 disease and 100 percent efficacy against severe COVID-19 , a press release by the Hyderabad-based company said on Wednesday.

The current efficacy rate is based on a second interim analysis of phase 3 clinical research data.

The vaccine's estimated efficacy against asymptomatic COVID-19 infection to be at 70 percent, the company claimed in the statement, adding that the efficacy against severe COVID-19 disease was 100 percent (95 percent confidence interval: 60-100), with an impact on reduction in hospitalisations.

The company didn't declare the sample size considered for the phase three interim analysis, however, it said that the efficacy rate was based on accruing more than 87 symptomatic cases of COVID-19 .

"Due to the recent surge in cases, 127 symptomatic cases were recorded, resulting in a point estimate of vaccine efficacy of 78 percent (95 percent confidence interval: 61-88) against mild, moderate, and severe COVID-19 disease," it added.

Chairman and Managing Director of Bharat Biotech Dr Krishna Ella said, "The efficacy data against severe COVID-19 and asymptomatic infections is highly significant, as this helps reduce hospitalizations and disease transmission, respectively.”

Bharat Biotech also said that the safety and efficacy results from the final analysis will be available in June, and the final report will be submitted to a peer-reviewed publication.

The Phase 3 study enrolled 25,800 participants between 18-98 years of age, including 10 percent over the age of 60, with analysis conducted 14 days post the second dose.

Professor Balram Bhargava, Secretary Department of Health Research & Director General, ICMR said, “I am very pleased to state that COVAXIN has shown the efficacy of 78 percent in the second interim analysis. I am also happy to note that COVAXIN works well against most variants of SARS-CoV-2.”

COVAXIN, which is being manufactured by Hyderabad-based Bharat Biotech was developed with seed strains received from the National Institute of Virology, and the phase 3 clinical trial was co-funded by the Indian Council of Medical Research.

"The efficacy data against severe COVID-19 and asymptomatic infections is highly significant, as this helps reduce hospitalisations and disease transmission, respectively,” said Dr Krishna Ella, chairman and managing director of Bharat Biotech.

The company also said that placebo recipients have now become eligible to receive two doses of COVAXIN.

Covaxin was approved and introduced initially through Emergency Use Authorization under the clinical trial mode, resulting in robust safety data in real-life conditions.