India to stick to 12-16 week gap between two Covishield doses

New Delhi: India will stick to the 12-16 week gap between two doses of Covishield, and review it after three months based on data from vaccination in local population, official sources said. The assertion comes even after the UK’s department of health suggested that two doses of Covid vaccine were required for “strong protection” against the new variant B.1.617.2 detected in India.

An official, who is a member of the National Technical Advisory Group on Immunisation (NTAGI) said Covishield’s earlier studies showed a protection of about 57% with a gap of four weeks, which increased to 60% when the second dose was delayed to eight weeks. With a 12-week gap, antibody protection was enhanced to 63%, he said. “But when we analysed real-life data from people vaccinated in UK, we found the protection with two doses with a gap of 12 weeks was 65-88%. Therefore, we decided to change the dosing schedule. It is a scientifically evaluated decision,” the official said.

The NTAGI has decided against any further changes in the dosing gap at the moment. Experts are of the view that the first dose generates adequate antibodies to protect from severe infection, whereas the second dose is primarily a booster shot that enhances the levels of protection.

Officials said the UK study data may require more clarity and there were some inconsistencies. “We have not taken our decisions in haste. We waited for live data and the change in our protocol or dosing gap was based on that large scale data,” the official said.

The NTAGI will review local data after three months from people who are being vaccinated.