Phase-3 Trials: Covaxin Demonstrates 100 Per Cent Efficacy Against Severe COVID-19, Overall Interim Clinical Efficacy 78 Per Cent

Bharat Biotech and the Indian Council of Medical Research (ICMR) on Wednesday (21 April) announced phase 3 interim analysis results of India's first indigenous COVID-19 vaccine, Covaxin.

In a statement, Hyderabad-based Bharat Biotech said that the second interim analysis is 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% (95%CI: 61-88) against mild, moderate, and severe COVID-19 disease," said the company.

The efficacy against severe COVID-19 disease was 100 per cent (95%CI: 60-100), with an impact on reduction in hospitalizations. The efficacy against asymptomatic COVID-19 infection was 70 per cent, suggesting decreased transmission in Covaxin recipients, the company said.

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, it added.

The company further said that based on the achievement of the success criteria, placebo recipients have now become eligible to receive two doses of Covaxin.

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

Covaxin 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, making it a true public, private partnership towards public health, it added.

Dr Krishna Ella, Chairman & Managing Director, Bharat Biotech, said, “Efficacy against SARS-Cov-2 has been established. Covaxin has demonstrated an excellent safety record in human clinical trials and in usage under emergency use. Covaxin is now a global innovator vaccine derived from Research & Development from India. The efficacy data against severe COVID-19 and asymptomatic infections is highly significant, as this helps reduce hospitalizations and disease transmission, respectively.”

The protocols for manufacturing, testing and release of inactivated vaccines have been tried, tested and validated across several of our vaccines; these also meet the requirements of WHO, Indian and other regulatory authorities, the vaccine maker said.

These protocols have delivered consistent results over a 15-year period with more than 300 million doses supplied globally, with excellent safety and performance record, it added.

Professor Balram Bhargava, Secretary Department of Health Research & Director General, ICMR, said, “I am very pleased to state that Covaxin, the first indigenous COVID-19 vaccine developed by ICMR and BBIL, has shown the efficacy of 78% in the second interim analysis. The tireless efforts of our scientists at ICMR and BBIL have resulted in a truly effective international vaccine of the highest standards and efficacy. I am also happy to note that Covaxin works well against most variants of SARS-CoV-2. These findings together consolidate the position of our indigenous vaccine in the global vaccine landscape.”

Several million doses of Covaxin have been supplied and administered in India and several other countries with an excellent safety record, evident by the minimal or lack of adverse events post-immunization, the company said.

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

Bharat Biotech further said that its efforts to further develop Covaxin will continue, with clinical trials planned in India and globally to evaluate the vaccine's safety and immunogenicity in younger age groups, the impact of booster doses, and protection against SARS-CoV-2 variants.