Keep Covid guard up at least till February

Scientists warned that the infections could spike to over 2.5 million new cases within a month if people abandoned personal protective measures such as masks and social distancing

G.S. Mudur   |   TT   |   New Delhi   |   19.10.20  :   India’s Covid-19 epidemic will end by February 2021 after three million more lab-diagnosed cases, a government panel of scientists predicted on Sunday, underscoring the need for rigorous adherence to mask norms, physical distancing and the no-crowding appeals.

The panel of mathematicians and medical experts said the epidemic had peaked in mid-September but new infections would continue to emerge until India’s cumulative case counts crossed 10 million by February-end, after which the epidemic would stop.

But the scientists also warned that the infections could spike to over 2.5 million new cases within a month if people abandoned personal protective measures such as masks, physical distancing and no-crowding.

Some scientists, however, said the study appeared handicapped by a lack of appropriate data.

Mathukumalli Vidyasagar, distinguished professor at the Indian Institute of Technology, Hyderabad, who led the effort, said: “We’re not saying that the infections will go to zero after February-end, but we should expect only minimal infections after that.”

Public health experts too have long predicted that at some point, the epidemic would cease and the infection enter an endemic phase during which a trickle of new infections would continue to emerge but no longer threaten to overwhelm hospitals.

While health experts have already recognised the downtrend in daily new infections since the mid-September peak of one million active patients, the new study is the first to forecast the numbers and a month for the end of the epidemic.

The study has estimated that the proportion of people already infected with the virus was about 14 per cent in August and has currently grown to around 30 per cent. People infected by the virus are viewed as not susceptible to infections in the near future and thus pose barriers to the spread of the virus.

“This mix of already infected and thus non-susceptible pool of people along with precautions such as masks and physical distancing over time makes it harder and harder for the virus to spread,” said Manindra Agrawal, professor of computer science at IIT Kanpur and a study team member.

The researchers have stressed that the epidemic’s end would not mean that any vaccines that might emerge would be redundant.

“We do not know how long people are protected after becoming infected — and even after the infection has become endemic, there would be a need for vaccines,” a medical expert involved in the study said.

The study has also predicted how India’s coronavirus disease counts, nearly 7.5 million on Sunday, would increase under various degrees of precautionary measures: from 17.6 million under no precautions at all, to 10.5 million under current restrictions to 8.3 million under stronger restrictions such as lockdowns.

“Lockdowns are now undesirable. Our data suggest that district or higher-level lockdowns will not be much effective now,” Vidyasagar said.

“However, localised lockdowns might be necessary in some areas if the increase in infections threatens to overwhelm the health facilities there.”

The modelling effort involved top experts from the IITs, the Indian Statistical Institute, Calcutta, and the office of the principal scientific adviser to the government. But the experts had to rely on crowd-sourced infection data instead of actual data from the Indian Council of Medical Research.

Two researchers involved in the effort said the study group had no access to ICMR data. A senior ICMR official declined to comment on the findings. Other officials were not immediately available to explain why ICMR data were not available to the research group.

An infectious disease specialist familiar with the research who requested not to be named said: “This is just another model. It is not clear what exactly it is telling us that we can act upon. An effort like this should have been done with reliable data six months ago.”

In line with earlier forecasts, this model too has suggested that the lockdown, which started on March 25, averted a sharp rise in infections that would have quickly overwhelmed India’s healthcare infrastructure. The study has estimated a peak load of over 14 million cases by mid-June had the lockdown not happened at all.

Had India waited till May to impose the lockdown, the peak load of active cases would have been about five million by June, according to the study that, the researchers said, has been accepted for publication in the Indian Journal of Medical Research.

“The emphasis on the lives saved by the lockdown is unusual since the comparisons are to a relatively unrealistic situation where no interventions happened at all,” said Gautam Menon, an infectious disease modelling expert at the Institute of Mathematical Sciences, Chennai, who was not associated with this effort.

“But the message about increased precautions to prevent spread in the festive season is important. I’m glad they have stressed this.”