Serum Institute informs Centre it will supply around 20 crore Covishield doses in September

By Express News Service

KOCHI: Do individuals who received a single dose of Covishield vaccine after recovering from Covid possess a higher level of immunity than those who have not contracted coronavirus? Yes, says a study conducted by a Kochi-based research centre.

The hybrid immunity (a hybrid of natural infection and one dose of vaccine) is expected to last in a person’s body for a longer time.The study was conducted by clinical immunologist and rheumatologist  Dr Padmanabha Shenoy and his team at CARE.

About 1,500 patients with autoimmune rheumatic diseases who have had Covid or were vaccinated were followed up to assess their immune response. Of these, 120 patients were selected to study hybrid immunity. Their anti-spike antibody was measured and ability to neutralise the virus was studied through viral neutralisation assays.

“Patients who received a single dose of Covishield after they had contracted the infection had 30 times higher antibody levels compared to those who received two jabs but were not infected. In the viral neutralisation assay, those with hybrid immunity could neutralise the virus much better than those who have received two doses of vaccine or had prior infection,” said Dr Shenoy. “Similarly, the study also shows that hybrid immunity is superior to the immunity developed following natural infection,” he added. Explaining the findings further, he said since a single dose of vaccine produces a high level of immunity in post-Covid patients, they may not need two doses. This may save close to 3 crore vaccine doses.

Similar studies were conducted on both vaccines earlier. The Asian Institute of Gastroenterology Hospitals, Hyderabad, conducted a study on Covishield and ICMR did it on Covaxin. They both revealed a single dose of either vaccine on the post-Covid-infected individual had a stronger immunity to the virus compared to those having no prior exposure.