People inoculated with mixed vaccines– first dose of COVISHEILD + second dose of COVAXIN and vice versa – in India were found with a much higher antibody response against SARS CoV-2 infectivity.  A clinical study conducted by a team of doctors at the AIG Hospital, Hyderabad, in 44 seronegative healthy volunteers divided into four groups with different combination of vaccines (two doses homogenous and heterogenous vaccines) with normal gap between doses in a 60-day observation, found that the mixing of vaccines not only safe with zero side effects but also elicited a four times higher antibody response against the virus infectivity.  The most important finding of the study was that the spike-protein neutralizing antibodies found in the mixed vaccine groups were significantly higher than the same-vaccine groups. This is particularly important when considering the third booster dose. The concept of a booster is to elicit robust antibody response and help in killing the virus. “Mixed doses can certainly boost these Spike-protein neutralizing antibodies and will enhance the vaccines’ effectiveness even against the Omicron variant,” said Dr. Nageswara Reddy, chairman, AIG Hospital, who was also part of the research team. The findings have been submitted to ICMR to be considered as a reference study, the hospital said.