A new research has revealed that neutralising antibodies against the Delta variant (B1.617.2) were not observed in 16.1% of the serum samples from those given two shots of the Oxford/AstraZeneca vaccine produced in India as Covishield.
The study by researchers of Indian Council of Medical Research (ICMR) has said that neutralising antibodies could not be detected in 58.1% serum samples from those given one shot of Covishield, manufactured by Serum Institute of India. This has again rekindled debate related to efficacy of vaccines against coronavirus, which is constantly mutating.
It is noteworthy that the Delta variant has already been declared as “variant of concern” by the Union Health Ministry, which has high transmission rate and severely attacks lung cells.
However, many experts believe antibodies not observed is not equivalent to not present. The levels of neutralising antibodies could be significantly low that it did not get detected, but it may still be there and protect the person against infection and severe disease.
The major takeaway of this study for India’s vaccination drive is that some people might require an additional booster shot of Covishield, while those who have had the infection may require just one.
As of now, India is only administering two dosages to people above 18 years old and there is no provision of additional booster shots to those not ‘developing antibodies’ after the final vaccine certificate.
On the other hand, health ministry officials have been advising people not to go for antibody testing after the completion of Covid-19 vaccination. On 27 May, Dr V.K. Paul, Member (Health), NITI Aayog, at a Union Health Ministry press conference, said that antibody levels were only one of the indications of immunity. “The advisable procedure to follow is to get vaccinated and adhere to Covid-19 appropriate behaviour,” he said.
Meanwhile, according to Health Ministry data, India reported 43,071 new Covid 19 cases on Sunday, making it seventh consecutive day when less than 50,000 daily new infections were detected. India has also been witnessing a continuous fall in the active caseload. The country’s active caseload stood at 4,85,350 on Sunday.
As more people are getting recovered from Covid-19 infection, India’s daily recoveries continue to outnumber the daily new cases for 52 consecutive days now. 52,299 recoveries were registered in the last 24 hours, the data stated.
The weekly positivity rate is currently at 2.44% while the daily positivity rate stands at 2.34%. The daily positivity rate has remained less than 5% for 27 consecutive days now.
The ongoing vaccination drive has also maintained its pace. India’s cumulative vaccination coverage crossed the landmark of 35 crore on Sunday. A total of 63,87,849 vaccine doses were administered in the last 24 hours as per provisional report released on 7 am on Sunday.