As many as 270 million people may have contracted Covid-19 in India, about 30 times the nine million reported.
The estimate by top virologist Jayaprakash Muliyil, has significant implications for herd immunity in the population.
Asked if the official figures were accurate, Dr Muliyil, chairman of the Scientific Advisory Committee of National Institute of Epidemiology said, “No”.
“You have to multiply it by 25 or 30, depending on where you are. Each area has its own number For India you have to multiply it by 30. That is a good level to achieve herd immunity.
“Herd level for rural areas is less since the population is much lower than slum areas.
Once you reach a level of herd immunity, the transmission will be much lower.”
According to official figures, India is the second-worst affected behind the United States, which has 12 million cases and more than 258,000 fatalities. Brazil the third worst affected has six million cases with 168,000 fatalities. The three account for about half of the 57 million cases globally. India stands third with 132,000 fatalities.
Dr Muliyil expects a slowdown in the number of new Covid cases in India, even as the National Capital Region of Delhi reported a spurt in both the daily number of cases as well as fatalities. The local administration was pulled up by a local court for not waking up to the task as the situation deteriorated with more people venturing out carelessly to celebrate the Diwali festival.
“A large number of urban India has got infected, so the disease finds it difficult to find a new host and that is the principle of herd immunity,’’ said Dr Muliyil, also a former principal of Christian Medical College, said from Vellore in south India.
He qualifies it to say that herd immunity typically would require more than half the population to get infected.
But India is made up of numerous heterogeneous pockets of high and low population densities. Most urban slums, with high population density, were among the first to get herd immunity with tests showing one-third to half the population displaying immunity.
Large pockets of affluent people may have protected themselves by avoiding mixing with a wider section of people to minimize the possibility of contracting the infection.
As these sheltered people begin to step out, it may be possible to see a spurt in the number of cases, as is probably the case in Delhi.
Likewise, herd immunity is likely to take longer in the sparsely populated rural areas, he said. The stage is over when many cities were scrambling for hospital beds, intensive care units, Covid beds and medical staff. He doesn’t expect any fresh wave to suddenly sweep across the country.
“Cases may not rise much from here, but there will be pockets across India,’’ he said. “Each area has its own starting and ending.’’
The strategy that he recommends is to ensure families and governments keep the elderly well protected.
“My advice to elderly people would be to stay guarded. Wear a mask, avoid crowds and be careful,’’ said Dr Muliyil. “If you do that India’s problems are solved.’’
More than 90% of fatalities are among people who are 60 years and older. Mortality among younger people is low and deaths generally happen if the virus combines with pre-existing conditions such as uncontrolled diabetes, hypertension or renal failure.
He said about 130 companies worldwide were busy developing a vaccine. They all knew one good thing about the disease, that it produces long-lasting immunity in people who have been infected.
“The vaccine will make everyone feel calmer,’’ he said. “It’s a silver bullet for the mind.’’
India could get a vaccine for widespread use between April and June. Still, several states and municipalities are maintaining restrictions to curb the chances of any spread. Mumbai, for instance, decided to keep all schools shut until December 31 even though cases are declining.
The National Capital Region of Delhi is facing multiple troubles with rising pollution, dipping temperatures and Covid cases surging officially past half a million, with 7,500 daily cases. The sudden spurt increased the rush for hospital beds, and reports suggest 90% of intensive care beds with ventilators were occupied on Thursday.
Laxity of administration before and during Diwali let people stray casually without the basic precautions of even a mask. After the court’s reprimand the Delhi administration increased the penalty for not wearing a mask to 2000 rupees from 500 rupees.
Ahmedabad, the capital of western state Gujarat, too has imposed weekend night lockdowns from Friday to reduce crowding and spread of the virus.