More than 60 million people in India -- 10 times the official figure -- could have contracted the novel coronavirus, the country's lead pandemic agency said, indicating the so called herd-immunity is still a far cry from ground reality.
According to official data India, home to 1.3 billion people, is the world's second most infected nation, with more than 6.1 million cases, just behind the United States.
But the real figure could be much higher, according to the latest serological survey -- a study testing blood for certain antibodies to estimate the proportion of a population that has fought off the virus.
"The main conclusions from this sero-survey are that one in 15 individuals aged more than 10 have been exposed to SARS-CoV-2 by August," Indian Council of Medical Research (ICMR) director-general Balram Bhargava said at a health ministry press conference.
The survey, conducted between August 17 and September 22, revealed that around 7.1 per cent of India's adult population (aged 18 and above) showed evidence of past exposure to the virus so far, reported our New Delhi correspondent.
It also said that for every confirmed Covid-19 case in August there were 26 to 32 infections that went undetected.
Bhargava said evidence of virus exposure was more prevalent among people tested in urban slums (15.6 percent) and non-slum urban areas (8.2 percent), than in rural areas, where 4.4 percent of those surveyed had antibodies.
The first survey conducted in May found sero-positivity was the highest in villages with 69.4 per cent compared to 15.9 per cent in urban slums and 14.6 per cent in non-slums.
TRUMP QUESTIONS INDIA DATA
US President Donald Trump on Tuesday also questioned the credibility of India's statistics on Covid-19 deaths, lumping in the US partner with nemeses China and Russia during a fiery pre-election debate.
Trump was responding to heated criticism from his Democratic rival Joe Biden, who blamed Trump for the heavy Covid-19 toll in the United States which has recorded more than 200,000 deaths and more than seven million infections.
"When you talk about numbers you don't know how many people died in China, you don't know how many people died in Russia, you don't know how many people died in India," Trump said at the debate in Cleveland.
"They don't exactly give you a straight count," he said.