In a study of 614 fully vaccinated health workers in India discovered a “significant” drop in their COVID-fighting antibodies within four months of the first shot.

This findings might help the Indian government to decide whether to provide booster doses. Some of the Western countries have done.

The director of a state-run institute said that the study Waning antibodies do not necessarily mean that immunized people may lose their ability to counter the disease, as the body’s memory cells may still kick in to offer substantial protection,.

“After six months, we should be able to tell you more clearly whether and when a booster would be needed, also we would urge similar studies in different areas for pan-India data.” Said Sanghamitra Pati of the Regional Medical Research Centre, based in the eastern city of Bhubaneswar.

British researchers said last month that the protection offered by two doses of the Pfizer/BioNTech and the AstraZeneca vaccines seems to fade within six months.

The Indian study, published in the Research Square pre-print platform but yet to be peer reviewed, is one of the first such done in the country involving its main two vaccines – Covishield, a licensed version of the AstraZeneca shot, and domestically developed Covaxin.

Health officials say though they are studying the evolving science on booster doses, the priority is to fully immunise India’s 944 million adults. More than 60% of them have received at least one dose and 19% the required two doses.

COVID cases and deaths in India have come down sharply since a peak of more than 400,000 infections in early May. India has reported 33.29 million cases in total and 443,213 deaths.