Research carried out in India’s commercial capital, the packed city of Mumbai, found that more than half of the residents of the slums examined in three areas of the city tested positive for antibodies to the coronavirus.
The survey showed that 57% of the people living in these densely populated areas may now be immune to the disease. While initially it was thought that producing antibodies after a Covid-19 infection might not confer immunity, the latest studies are now strongly suggesting that strong, lasting immunity may be gained by people who developed even mild symptoms of the disease.
The Mumbai results come from random testing of some 7,000 people in three of the poorest areas of the cities in early July, carried out by government think-tank Niti Aayog and the Tata Institute of Fundamental Research.
Covid-19 is more likely to spread quickly in crowded, densely populated areas where sanitation is poor. In Mumbai’s slums, where up to 6 million people live, households often share the same public toilet and have limited access to running water.
The survey indicates that, as indicated by the WHO, the vast majority of people who got Covid-19 will recover and not need hospitalisation. Many, of course, are asymptomatic, and, as noted above, new evidence shows that having caught Covid-19, most will now be immune to the disease.
This leads to speculation that areas recording the kind of prevalence and recovery as Mumbai, may now be close to achieving herd immunity, but only time will tell if that is, in fact, the case.
There’s a price to pay for herd immunity of course, with one news report suggesting that Mumbai may have a much higher Covid death rate than the rest of the country, although its difficult to quantify how much of those deaths would have been preventable with better access to healthcare and improved public education. “The high death rate is because of high co-morbidities like hypertension and diabetes. Many of those who died did not report their condition on time or go to a doctor,” the news report suggests.
India recently hit a high of Covid case numbers, with some 2 million infections recorded, a peak that occured after the country opened up again to try to protect its economy, but the overall death rate for the country (the percentage of those contracting the virus who die) at under 2% compares favourably internationally with more developed economies sometimes recording twice that percentage of deaths.
The findings of the Mumbai survey will add to the growing debate as to how to best manage the spread of Coronavirus while also protecting the economy and the well-being of the people.
Máirín De Barra writes from Dublin