Covaxin demonstrates 81% efficacy, says Bharat Biotech on Phase 3 results Covaxin is one of two Covid vaccines that was granted emergency use approval in the country in early January. File Photo Updated: Mar 3, 2021, 07:44 PM IST Bharat Biotech's coronavirus vaccine 'Covaxin' demonstrated an interim efficacy of 81% against COVID-19, the company announced on Wednesday while releasing the results of Phase 3 clinical trials. “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,” said Dr Kirishna Ella, Chairman and Managing Director of Bharat Biotech.