The study examined 18 individuals in UP who inadvertently received Covishield as the first jab and Covaxin as the second. "The findings suggest that immunisation with a combination of an adenovirus vector platform-based vaccine followed by an inactivated whole virus vaccine was not only safe but also elicited better immunogenicity," the pre-print of the ICMR study published in MedRxiv says.The study examined 18 individuals in UP who inadvertently received Covishield as the first jab and Covaxin as the second. "The findings suggest that immunisation with a combination of an adenovirus vector platform-based vaccine followed by an inactivated whole virus vaccine was not only safe but also elicited better immunogenicity," the pre-print of the ICMR study published in MedRxiv says.