One third of the country—around 40 crore people—have no antibodies against SARS-CoV-2, reveals the Indian Council of Medical Research's (ICMR) fourth national sero survey. Announcing the survey results, ICMR chief Balram Bhargava said that state heterogeneity indicates the possibility of future waves.
"There is no room for complacency,'' he said, stressing that societal, public, religious and political congregations and non-essential travel have to be avoided. "Travel only after being fully vaccinated,'' he advised.
The sero survey, which looks for the presence of antibodies to the virus in the blood, was conducted over the last ten days of June and the first few days of July. For the first time, the ICMR also took into account children (6 to 17 years), who are not covered by vaccination yet. The survey size was of 28,975 volunteers, from the same 70 districts across 21 states. The survey shows that the sero prevalence is similar among minors to that of the adults. In the 6-9 years age group, the positivity was 57.2 per cent, in the 10-17 group 61.6 per cent, in the 18 -44 group 66.7 per cent, in the 45-60 group 77.6 per cent and in the 60 plus group 76.7 per cent.
The sero positivity at the end of December 2020 was around 25 per cent. In the second survey (August-September 2020), it was less than 10 per cent and in the first survey in May – June 2020, it was 0.7 per cent. “There is a ray of hope, but no room for complacency,” said Bhargava, adding that this survey cannot be a substitute for district-level surveillance. NITI Aayog member Dr V.K. Paul added that in Kerala, cases were still rising, while in Maharashtra it had just become static.
The experts stressed on the need to get the country's population vaccinated, saying that antibodies in the remaining 40 crore people should come from vaccines, not infection. The high level of sero positivity in the fourth survey, they said, was a combination of both vaccination and the second wave of infections. It was a cause for concern that 10 per cent of the health care workers in the survey had not yet taken the vaccine.