Bharat Biotech releases Phase 3 results of Covaxin, says it shows 81% interim clinical efficacy Bharat Biotech releases Phase 3 results of Covaxin, says it shows 81% interim clinical efficacy Bharat Biotech has announced Phase 3 clinical trial results of Covaxin, saying the vaccine demonstrates interim clinical efficacy of 81 per cent. advertisement Bharat Biotech said Phase 3 clinical trials for Covaxin involved 25,800 volunteers. Bharat Biotech said the Phase 3 clinical trials for Covaxin involved 25,800 volunteers, making it the "largest trials ever conducted in India" in collaboration wit...