The National Technical Advisory Group on Immunisation (NTAGI) which reviewed the data of Corbevax earlier had found significant antibody response when it was given as a third dose to those who have received two doses of Covishield and covaxin.
“We reviewed the data and found significant antibody response in both the groups i.e those who have got Covishield and Covaxin,” a person in the know told ET. Adding that it’s inclusion as a heterologous booster will be made by the government. Corbevax was cleared by the Drug Controller General of India as a booster.
So far India has been using the same vaccine used in the first two shots for the precaution, or third dose since January though it approved Corbevax as a booster.
Hyderabad based Biological E had earlier said that the booster dose of Corbevax “increased the neutralising antibody titers in the Covishield and Covaxin groups significantly when compared to placebo.”
BE had conducted a multicentre Phase III placebo controlled heterologous booster clinical trial in 416 subjects from 18 to 80 years of age who were previously vaccinated with two doses of either Covishield or Covaxin at least six months prior to the administration of Corbevax as a booster dose.
“In a subset of subjects evaluated for nAb (neutralising antibodies) against the Omicron variant, the Corbevax booster shot resulted in a significant increase in the nAb titers against the Omicron variant. After the booster dose of Corbevax, Omicron nAbs were observed in 91% and 75% of subjects who had received primary vaccination by Covishield and Covaxin, respectively,” it had said.
Experts believe that India needs to update its booster policy, amid the emergence of BA.2.75. They say the current policy is not making the best use of evidence and available vaccine choices.