Coronavirus | 60 million Indians may have been exposed to COVID-19: ICMR sero-survey

Around 7% of India’s adult population may have been exposed to the coronavirus till the last fortnight of August, according to the second national sero-survey by the Indian Council of Medical Research (ICMR).

The people tested in the second survey were drawn from the same villages and clusters as the first, in which the scientists said that 0.73% of adults — or about 6.4 million — across the country were likely infected.

Because it is yet unclear how long antibodies to the coronavirus detectably persist in the body, their presence only indicates past exposure to — and not presence of — the virus.

During the first survey, it emerged that there were 82-130 infections for every confirmed COVID-19 positive case.

In September there were 29 million tests, compared to 23 million in August, 10.5 million in July and 30,000 in March according to Health Secretary Rajesh Bhushan.

However, the numbers also suggest that the country still has an overwhelming majority of its population yet to be exposed to the virus and therefore, is far from any peak’ or ‘herd immunity’ levels.

These refer to approximate estimates that show what percentage of the population needs to be exposed to the virus so that the its spread is curtailed.

“The risk of being exposed to the virus is real and we have to continue with our measures.

One in fifteen individuals above 10 were exposed to the virus by August and there was no difference by age group and gender.

The country wide prevalence of the virus was similar to that seen in the United States, which was around 9.3%.

The lower rate of confirmed cases to true infections was due to an increase in testing as well as the large scale deployment of rapid antigen tests (these are quick tests to determine the presence of virus but also tend to substantially miss infections). .

“The opening up of the country has no doubt seen the virus spread and it is quite likely that these numbers will increase in the coming months?

The sero-survey, because it aims to capture national prevalence, samples many more from rural India than cities to reflect the population spread in the country.

On May 3, there were 49,720 confirmed cases in India and 3.7 million ones by September 1 — a 74-fold increase.

As of Tuesday, India has recorded 6.1 million confirmed infections, of which about 9,50,000 are active cases.