Hyderabad: A mix and match of Covishield and Covaxin has the ability to elicit a robust antibody response against SARS-CoV-2, a pilot study taken-up by city-based Asian Institute of Gastroenterology (AIG) Hospitals on Monday said. The AIG study also has indicated that 87 percent of the participants in the study, who were not vaccinated and never tested positive for Covid, had Covid antibodies.
The pilot study is quite significant in the context of the upcoming precaution or booster doses, which are going to be launched from January 10. The concept of a booster dose is to elicit robust antibody response and help in killing the virus. Mixed doses of Covishield and Covaxin can certainly boost spike- protein neutralizing antibodies and will enhance the vaccines’ effectiveness even against the Omicron variant, founder and chairman, AIG Hospitals, Dr D Nageswar Reddy here on Monday said.
Mixing of Covishield and Covaxin elicited higher antibody response from the body and are safer, the study said. “Mixing of vaccines is absolutely safe as none of the participants in the study developed any adverse effect. We found that when the first and second dose are from different vaccines, then the spike-protein antibody response is four times higher compared to two-dose of the same vaccine,” Dr D Nageswar Reddy said.
The doctors at AIG Hospitals in collaboration with Asian Healthcare Foundation conducted the pilot study to determine the safety profile of mixing Covishield and Covaxin and checking the antibody response. A total of 330 healthy volunteers who were not vaccinated and had no history of Covid infection were selected and screened for SARS-CoV-2 antibodies for the study. Out of the 330 study volunteers, a total of 44 participants (13 percent) were found to be seronegative, i.e., they didn’t have COVID-related antibodies.
“One of the incidental findings of the study is the seropositivity among our population. Our study also indicated that about 87 percent of participants who didn’t get vaccinated and never tested positive Covid but had Covid-related antibodies. This means our population might have developed significant antibodies against the Covid because of the huge Delta wave that we endured,” said Dr. Nageshwar Reddy said.
The AIG study indicated that the spike-protein neutralizing antibodies found in the mixed vaccine groups were significantly higher than the same-vaccine groups. “Spike-protein neutralizing antibodies are the ones that kill the virus and reduce overall infectivity. We found that when the first and second dose are of different vaccines, the spike-protein antibody response is four times higher compared to two-dose of the same vaccine,” Dr Reddy, who was also part of the study, said.
Following the study results, the senior researchers at AIG Hospitals have shared the data from the study with the Indian Council for Medical Research (ICMR). The application of mixed doses of Covid vaccines can be considered as a reference study while deciding on the ‘Prevention’ doses that start from January 10, Dr Reddy added.