Mumbai/Hyderabad: COVID-19 vaccines — Covishield and Covaxin — could produce a high immune response in up to 95 per cent of recipients and prevent serious disease in those infected after inoculation, a ‘real-world’ study of the vaccinated healthcare officials found.
A pre-print of the first such Indian study stated that Oxford vaccine Covishield could generate antibodies in more individuals in comparison with Bharat Biotech’s Covaxin. Most studies of vaccine efficacy so far have been laboratory-based.
A pan-India study was done on 515 healthcare workers who have already been vaccinated. Among them, 425 took Covishield and 90 Covaxin from 13 states and 22 cities. The study found the vaccines could generate an immune response in 95 per cent of recipients 21-36 days after taking the second dose, reported The Times of India.
Seropositivity was observed in 98 per cent of those who took Covishield as against 80 per cent for Covaxin recipients. The researchers called the finding “surprising”.
According to lead author and endocrinologist Dr Awadhesh Kumar Singh of GD Hospital & Diabetes Institute, Kolkata, the study was not conducted to comment on which vaccine is better but to look at the vaccination’s real-world effectiveness.
“In the absence of measuring neutralising antibody and cell-mediated response, it is difficult to comment whether one is superior,” Dr Singh said.
“In individuals who have had Covid infection, both vaccines are equally good and could produce high antibodies even after a single shot. But for those who haven’t got Covid, Covishield could provide an edge,” Dr Singh added.