- The heterologous booster is being pursued by several countries across the world over the last few months. Many scientific and medical experts believe that the heterologous booster works better in developing antibodies to fight the virulent virus and its variants. However, the Indian authorities were not sure about going ahead with the measure as concerns were expressed from different quarters. Nonetheless, it appears those concerns were adequately addressed as the Drug regulator DCGI has approved administering Biological E’s Corbevax, a protein subunit recombinant vaccine, as the first heterologous booster for adults. Now, this move clears the decks for a shift articulated by other experts since late 2021.
PC: Surbhi Pathak
- The next logical step would be for the National Technical Advisory Group for Immunisation (NTAGI), comprising government and independent experts, to recommend its induction into the precaution dose programme. Even though the health ministry has skipped this process while approving Corbevax for 12-14-year-olds. As mentioned above, many subject experts have been advocating a mix-and-match strategy for months. Of course, they were doubtful about viral vector and inactivated virus vaccines generating high volumes of neutralizing antibodies as homologous boosters. Significantly, Corbevax’s Phase 3 mix-and-match trials showed a substantial increase in neutralizing antibody titers against the Omicron variant.
- This should prod the Government of India to make the said vaccine of choice in administering precaution doses. For the record, over 5.2 crore Corbevax doses have been administered to children below 18 so far and Bio E has reportedly supplied 10 crore doses to the Government of India. Evidently, the low offtake of boosters, not supply, is the big problem now as complacency and general disregard for the mask mandate appear to be on the rise. Taken together, it calls for a changed outreach strategy beyond bulk SMSs with Omicron infections increasing across multiple states in recent days. It remains to be seen if the regulator’s six-month gap for administering Corbevax after the second dose of Covishield or Covaxin will be echoed by NTAGI too.
PC: IANS
- The glaring anomaly vis-à-vis the nine-month gap between homologous boosting needs to be addressed immediately. As reported, a National Institute of Virology Pune study had shown that Omicron neutralizing antibodies waned after six months for those fully vaccinated with Covishield or Covaxin. Yet the nine-month gap hasn’t changed and must be reviewed now. With Bharat Biotech’s intranasal vaccine and Covovax in the race to become heterologous boosters, the availability of a wider vaccine bouquet is a welcome development. Moreover, the number of government vaccination centers offering free precaution doses must be increased as well. People will flock to free vaccination centres. And there should be no room for complacency either.
