Monday, 05 July 2021 | PNS | New Delhi
Neutralising antibodies against the Delta variant (B1.617.2) of Covid-19 were not found in at least 16.1 per cent samples from those who had been administered both doses of the Covishield vaccine, as per a study conducted by researchers from the Indian Council of Medical Research (ICMR). The study is yet to be peer reviewed.
On the other hand, neutralising antibodies were not observed in 58.1 per cent of serum samples from those who had been given only one shot of Covishield. Neutralising antibodies are proteins produced by the body to block pathogens, i.e. bacteria or viruses from infecting host cells.
Reacting to the study, Dr Rahul Bhargava, Director-Bone Marrow Transplant Programme, Fortis Memorial Research Institute, Gurugram said, “It is not surprising to see that 16 per cent did not develop antibodies. But what is more important is which is this subset who has not mounted the response? They need to be identified and revaccinated with an alternative vaccine.”
This also suggests that there is a need for a second booster to enhance antibodies, he added.
This means that some people in India may require an additional booster shot of Covishield. On the other hand, those who have had Covid-19 may require just one shot to develop an adequate immune response, say experts.
The study also found that the titres of neutralising antibodies generated by the vaccine, which specifically target the coronavirus and kill it, were lower against the Delta variant when compared with the B1 strain which led to the first wave in India.
