The fourth national serosurvey carried out by the Indian Council of Medical Research (ICMR) indicates that more than two-thirds of India’s population have developed antibodies against COVID-19.
Conducted between June and July of 2021, the survey’s findings found 67.6 percent of the country’s 1.3 billion people presented with antibodies. This marks a substantial increase from the third serosurvey carried out between December 2020 and January 2021 which estimated seroprevalence to be 24.1 percent.
The highest prevalence of antibodies was found in the 45-60 age demographic, at 77.6 percent, followed by those aged over sixty, at 76.7 percent. Among those aged eighteen to 44, the prevalence stood at 66 percent. Seroprevalence among urban areas stands at 69.6 percent – 3.1 percentage points higher than in rural areas. Among women who participated, 69.2 percent presented with antibodies as opposed to 65.8 percent of males.
ICMR director-general Dr Bharam Bhargava welcomed the news, but urged continued vigilance. “The findings clearly show that there is a ray of hope but there is no room for complacency,” he said, noting that 400 million Indians present without antibodies and so are at heightened risk of contracting the virus. It is also worth noting that infection with COVID-19 is still possible even if one is fully vaccinated or has previously contracted the novel coronavirus.
Factors contributing to the substantial increase may include the high number of infections witnessed during the country’s second wave and the rollout of the country’s vaccination drive. However, it is worth noting that of those surveyed, 62.2 percent had yet to be vaccinated with just 24.8 percent partially vaccinated and a mere thirteen percent fully inoculated – underscoring concerns over a vaccine rollout described by some commentators as “lagging.” One finding of the serosurvey was that one in ten healthcare workers are unvaccinated, although the group has a healthy seropositivity of 85.2 percent.
Recent research found that antibodies from infection with COVID-19 can last at least nine months in most people who contract the virus. Researchers in Italy tested 85 percent of the 3,000 residents of the town of Vo and found that, of those infected in the first wave, 98.8 percent still presented with antibodies nine months later. There was no difference between those with asymptomatic or symptomatic infections.
