Govt may not allow mixing of Covid vaccines for booster shots

NEW DELHI: The government may not allow precaution dose of a COVID-19 vaccine other than the one used for primary vaccination in light of a CMC Vellore study which showed lack of uniformity in results upon mixing of jabs for booster shots, sources said on Thursday.

The Covid Working Group of NTAGI stated that scientific evidence showed that administering a booster dose of Covishield after primary vaccination with Covaxin gives 6 to 10 times higher antibody level as compared to when Covaxin is given as the precaution dose after a gap of six months after the primary schedule.

"However, the same advantage was not observed when Covaxin as a booster shot was given after two Covishield doses," an official source said.