Covaxin phase 3 trial data released: Jab shows 65.2% efficacy against Delta COVID-19 variant, says company

Covaxin coronavirus vaccine has overall efficacy of 77.8 percent against symptomatic cases, while the indigenously developed jab showed an efficacy of 65.2 percent against the highly transmissible Delta variant of COVID-19, vaccine maker Bharat Biotech said citing the Phase 3 clinical trial data.

"Phase 3 clinical trials of Covaxin were an event-driven analysis of 130 symptomatic COVID-19 cases, reported at least two weeks after the 2nd dose, conducted at 25 sites across India," the company's statement said.

The data, however, is yet to be peer-reviewed.

Labeling its research as "India's largest-ever COVID-19 vaccine trial", the company added that the overall efficacy figure was arrived at after 24 volunteers who were given the vaccine tested positive for COVID-19 out of a group of 130 confirmed cases.

The efficacy analysis of Covaxin also demonstrated the effectiveness of 93.4 percent against severely symptomatic COVID-19 infections, the company said. The safety analysis showed "that adverse events reported were similar to placebo, with 12 percent of the subjects experiencing commonly known side effects and less than 0.5 percent faced serious adverse events".

The company also claimed that the overall rate of adverse events observed "was lower than that seen in other COVID-19 vaccines".

On the other hand, the efficacy was 63.6 percent for patients who had asymptomatic COVID-19 infections. "Covaxin is the first to report promising efficacy against asymptomatic infections based on qPCR testing that will help in reducing disease transmission," the statement said.

Dr Krishna Ella, Bharat Biotech's chairman and managing director said, "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."

Indian Council of Medical Research (ICMR) director-general Balram Bhargava echoed his Ella's statement.

He said, "I am delighted to note that Covaxin developed by ICMR and BBIL under an effective public private partnership, has demonstrated an overall efficacy of 77.8 percent in India’s largest COVID phase 3 clinical trial thus far. Our scientists at ICMR and BBIL have worked tirelessly to deliver a truly effective vaccine of highest international standards.

"Covaxin will not only benefit the Indian citizens but would also immensely contribute to protect the global community against the deadly SARS-CoV-2 virus. I am also pleased to see that COVAXIN® works well against all variant strains of SARS-CoV-2. The successful development of COVAXIN® has consolidated the position of Indian academia and Industry in the global arena."