Covaxin has an overall efficacy of 77.8 per cent against symptomatic COVID-19 says Bharat Biotech as it concludes safety and efficacy analysis from Phase 3 clinical trials

A health worker prepares a jab of Covaxin vaccine at a free vaccination camp in Siliguri on July 3.

Covaxin, the COVID-19 vaccine developed by the Hyderabad-based pharmaceutical major Bharat Biotech in collaboration with the Indian Council of Medical Research (ICMR) and the National Institute of Virology, has been found to be 77.8 per cent effective in the Phase 3 clinical trials against symptomatic COVID-19.

Covaxin has also been found to be 93.4 per cent effective against the severe symptomatic form of COVID-19 and 63.6 per cent effective against asymptomatic COVID-19. In its Phase 3 clinical trials, Bharat Biotech had conducted an event-driven analysis of the whole virion-inactivated Covaxin vaccine against severe acute respiratory syndrome coronaviruses (SARS-CoV-2) on 130 symptomatic COVID-19 cases reported at least two weeks after the second dose at 25 sites across India.

Releasing the results of the safety and efficacy analysis data from the Phase 3 clinical trials in the wee hours of July 3, Bharat Biotech declared that Covaxin has also been found to demonstrate a 65.2 per cent effective protection against the dreaded SARS-CoV-2, B.1.617.2 Delta variant. Over the past few weeks, it is the Delta variant strain of the Coronavirus that has shown to be the dominant strain among the COVID-19 viruses across the world.

Bharat Biotech highlighted in its media release that it was the first COVID-19 vaccine manufacturer to publish data on efficacy results against asymptomatic infection in a randomised controlled trial based on qPCR testing. Stated the company: “No licensed SARS-CoV-2 vaccine has reported efficacy against asymptomatic infection in a randomised controlled trial, based on qPCR testing. Covaxin is the first to report promising efficacy against asymptomatic infections based on qPCR testing that will help in reducing disease transmission.”

On safety concerns, Bharat Biotech claimed that Covaxin was well tolerated and that the Data Safety Monitoring Board has not reported any safety concerns related to the vaccine, and the overall rate of adverse events observed in Covaxin was lower than that seen in other COVID-19 vaccines. Said the statement from Bharat Biotech: “The safety profile of Covaxin is now well established based on inactivated vaccines technology, and in large part due to the extensive 20-year safety track record of Bharat Biotech’s vero cell manufacturing platform. Furthermore, Bharat Biotech has so far not sought indemnity for Covaxin from the governments.”

The company said that the safety analysis of Covaxin demonstrated that the adverse events reported after vaccination with it were similar to placebo, with 12 per cent of the subjects experiencing commonly known side effects and less than 0.5 per cent of subjects feeling serious adverse events.

Said Dr Krishna Ella, Chairman and Managing Director, Bharat Biotech: “The successful safety and efficacy readouts of Covaxin as a result of conducting the largest ever COVID vaccines trials in India establishes the ability of India and developing world countries to focus towards innovation and novel product development. We are proud to state that innovation from India will now be available to protect global populations.”

Dr Balram Bhargava, Secretary, Department of Health Research and Director General, Indian Council of Medical Research, said: “I am delighted to note that Covaxin, developed by ICMR and Bharat Biotech under an effective public-private partnership, has demonstrated an overall efficacy of 77.8 per cent in India’s largest COVID Phase 3 clinical trial thus far. Our scientists at ICMR and Bharat Biotech have worked tirelessly to deliver a truly effective vaccine of the highest international standards. Covaxin will not only benefit Indian citizens but would also immensely contribute to protecting the global community against the deadly SARS-CoV-2 virus.”