The third national serosurvey conducted by the Indian Council of Medical Research from December 17 to January 8 to check for antibodies against the coronavirus in random samples of people who did not have known infection has found that 21.5 per cent of the population (1.38 billion) has evidence of antibodies to the pathogen. This means that nearly 30 crore people have possibly had the disease, though the national Covid tally reflects just a tad over one crore. Notably, this indicates a rise in the number of people who may have had Covid-19 since the first two surveys done in the same 70 districts and cities.
The second serosurveillance pointed to over 6.6 per cent of the individuals having been exposed to the virus by August. It also found that for every reported case, there were 26-32 actual cases of infection. In other words, there were around 9-11 crore Covid cases when the official figure was only 35 lakh. The first serosurvey held in May-June recorded an overall seropositivity of 0.73 per cent and 82-130 cases of possible infections for every reported case.
The rising seroprevalence is reassuring as it contributes to boosting immunity to the virus. A heartening reflection of this is the steady decline in the number of Covid-positive patients in the past few months, as also the reduction in the Covid-19 positivity rate from 8.89 per cent on August 4 to 5.42 per cent on February 4. But some worrisome trends continue and must be tackled. The weekly positivity rate of eight states and UTs is higher than the national average of 1.82 per cent, including that of Chandigarh (2.10 per cent). The Covid management strategy must focus on Kerala and Maharashtra — the two states that have, of late, been contributing to 70 per cent of the active cases — to contain its spread. The ongoing vaccination drive is equally essential to expedite the taming of the virus. Meanwhile, with almost 78 per cent people still vulnerable to contracting the disease, letting go of Covid-appropriate behaviour will cost dearly. Letting go of masks, sanitisers and social distancing is not yet an option.