A new study from the Indian Council for Medical Research (ICMR) and summarized in Statista provides a sobering estimate of just how dangerously infectious the Delta variant of Covid-19 really is.
Back in February, at the conclusion of the first wave of Covid-19 to strike India that peaked the previous September, but before the start of their second Delta-driven surge, the results of the third seroprevalence survey by the ICMR had found that about 21% of the Indian population had developed antibodies by then for the Sars-CoV-2 coronavirus that causes Covid-19. By contrast, the officially confirmed number of cases at the time stood at about 10.8 million — a total infection rate of less than 0.8%.
By contrast, this fourth and most recent seroprevalence survey that wrapped up earlier this month during the waning stages of this Delta-driven surge found that nearly 68% of the entire Indian population now contained the Covid-19 antibodies! So while it had taken about 9 months for the original and early variants of Covid-19 to infect 21% of the Indian population, it took the mostly Delta variant to infect a further 47% of the entire population in just 4 months — and that’s ignoring any potential reinfections.
And since the official stats recorded less than twice the number of new cases (about 20 million, or an additional 1.4% of the total population) during this second surge, it’s clear that India’s already problematic record keeping was even less successful in keeping up with the Delta variant. This also helps explain why the IHME for example projects that India has already lost close to 1,2 million people to Covid-19 thus far, rather than the “official” statistic of ~420,000 dead, and why some researchers on the ground in India think the true death toll may already be closer to 4 million.
The one ray of hope, at least for India, is that if this latest seroprevalence survey is reasonably accurate, they are much less likely to suffer anywhere near as much in a future surge simply because so much of the population has already been exposed by now. OTOH, with some 400 million remaining who are still both unexposed and unvaccinated, it’s still quite possible that locally severe outbreaks could still arise, particularly where a vulnerable population is geographically concentrated; and if some newer variant should arise that can seriously degrade the effectiveness of our current vaccines and/or cause substantial reinfections in the previously exposed, then all bets are off.
As for the rest of us, we have been warned now that the Delta variant is deadly serious in its ability to sweep through vulnerable populations far more rapidly than we might have originally imagined.