New Delhi, June 4: Hyderabad-based vaccine manufacturer BiologicalE’s protein subunit Covid-19 vaccine Corbevax has become the first to be approved by the country’s drug regulator as a heterologous booster in adults, meaning those who have received Covishield or Covaxin as their first two doses can take Corbevax for their third shot.

So far, mixing and matching Covid-19 vaccines was not allowed in India and the third dose had to be of the same vaccine used for the first and second doses. With the Drugs Controller General of India (DCGI) now approving the heterologous booster, the government will have to take a call on whether it would be included in the country’s free vaccination drive.

“BE’s clinical trial data showed that CORBEVAX® booster dose provided significant enhancement in immune response and excellent safety profile required for an effective booster,” the company said in a release.

The approval came after a trial was conducted in 416 persons who were administered Corbevax or placebo (an agent with no therapeutic value) six months after having received two doses of either Covaxin or Covishield. The company, in its release, stated that the levels of neutralising antibodies – antibodies that specifically attack or block the Sars-CoV-2 virus – increased significantly in those who had taken Corbevax as compared to the placebo.

According to the Indian Media, After the booster dose of Corbevax, neutralising antibodies against the Omicron variant of the Covid virus were found in 91% of those who had received Covishield before and in 75% of those who had received Covaxin.

The company also found cell-mediated immunity to be higher in those who had received the Corbevax shot as compared to the placebo. “The Corbevax heterologous booster vaccine was well tolerated and safe. There were no severe or adverse events of interest for 3 months of follow-up after the booster dose was administered,” the company said.

Currently, the vaccine is in use for immunisation of children between the ages of 12 and 14 under the government programme. It is also available on payment for children between 12 and 17 years at private vaccination centres.

The company said that so far 51.7 million doses of the vaccine have been administered to children across the country, with 100 million doses having been supplied to the government of India.