MUMBAI/HYDERABAD: A ‘real-world’ study of vaccinated healthcare workers has found Covishield and Covaxin could produce a high immune reaction in up to 95% recipients and stop serious disease in those infected after immunisation. Interestingly, the Oxford vaccine Covishield could generate antibodies in additional individuals compared to Bharat Biotech’s Covaxin, a pre-print of the primary such Indian study has stated. Most vaccine efficacy studies thus far are lab-based. The pan-India study of 515 vaccinated healthcare workers — 425 with Covishield and 90 with Covaxin — from 13 states and 22 cities found the vaccines could generate an immune reaction in 95% recipients 21-36 days after the second dose.
Seropositivity was observed in 98% of these immunised with Covishield as against 80% Covaxin recipients, a finding the researchers called “surprising”.
Even the anti-spike antibody titre was found to be significantly higher in Covishield recipients (115 AU/ml) compared to Covaxin (51 AU/ml).
While factors like gender, BMI and other comorbidities didn’t seem to play much of a task , the seropositivity rate or antibodies in people above 60 years or those with type 2 diabetes was found to be significantly lower.
Seropositivity rate was significantly more in participants with age but 60 years (96.3% seropositivity) as against 87.2% within the 60-plus bracket. Infection post vaccination was seen in 5% of the study group, but none suffered from severe Covid-19.
Lead author and endocrinologist Dr Awadhesh Kumar Singh of G D Hospital & Diabetes Institute, Kolkata, said the study wasn't to discuss which one may be a better vaccine, but to seem at the real-world effectiveness of vaccination.
“In the absence of measuring neutralising antibody and cell mediated response, it's difficult to comment whether one is superior,” he said. Results of the Cross-sectional Coronavirus Vaccine-induced Antibody Titre (COVAT) study were published in pre-print server MedRxiv on June 4.
“In individuals who have had Covid infection, both vaccines are equally good and will produce high antibodies even after one shot. except for those that haven’t got Covid, Covishield could provide a foothold ,” he said.
