Two-thirds of India's population has Covid antibodies: ICMR's serosurvey

Two-thirds of India’s general population has Covid antibodies, according to the fourth national serosurvey conducted by Indian Council of Medical Research between last weeks of June and early July this year.

The overall seroprevalence in the country was around 67.6 per cent. While children in the age group 6-9 years showed the lowest exposure to Covid, over 57 per cent of them showed antibodies.

Despite high seropositivity shown in data, the government has cautioned that around 400 million people in India were still vulnerable to the virus.  “The rise in seroprevalence is due to two factors - the second wave and also the vaccinations which has given some seroprotection to people,” said V K Paul, chairman, national Covid task force and member-Niti Aayog.

Seroprevalence-- the presence of Covid antibodies was much higher in those who were vaccinated with one dose and highest among the fully vaccinated at 81 and 89 per cent respectively.

“The findings clearly show that there is a ray of hope, no room for complacency. We have to maintain covid appropriate behavior and community engagement,” said Balram Bhargava, director general, ICMR.

Covid exposure among those surveyed was slightly higher in urban - areas - 69.6 per cent compared to the rural - 66.7 per cent. With 69.2 per cent seroprevalence more females showed the C0vid antibody presence than male - 65.8 per cent.

The last serosurvey conducted towards the end of first wave in December-January had shown that around 24 per cent of population was exposed to Covid.

Besides 28,975 people from the general population, the ICMR survey also studied 7,252 health care workers. More than 85 per cent of the healthcare workers showed the antibodies presence. Ten per cent of the health workers were not vaccinated.

Areas without antibodies still run the risk of infection, ICMR has warned.

While the latest survey gives a bird’s eye view of the spread of Covid-19 in India following the second wave, ICMR stressed that the national serosurvey is not a substitute for local variations at states and districts level. “State-led sentinel sero-surveillance will inform further state-level action. State heterogeneity indicates possibility of future waves of infection,” Bhargava said.

Government has discouraged all non-essential travel and advised people to travel only if fully vaccinated. It has also said that all societal, public, religious and political congregations have to be avoided.

The serosurvey was conducted in the same 70 districts across 21 States that were part of the last three such studies. Ten villages or wards from each district were represented with 40 individuals per village or ward. Ten per cent of those surveyed were children in a departure from previous samples. More than 62 per cent of those surveyed among adults had not taken any vaccine dose.