Experts Question Study Predicting Fourth Covid Wave In June, Term Such Forecasts Guesswork

Forecasting models are good only for short-term projections and an IIT-Kanpur study predicting a fourth Covid wave in India in June may at best be "data astronomy" and guesswork, say several scientists.

Dispelling fears of another spike in cases in the next three months, they also took note of the fact that most people in India have had two vaccines and one natural infection. So even if there is a wave, the consequences in terms of hospitalisation and deaths should be manageable unless there is a new variant.

"Active cases are decreasing quite fast - and from looking at the current trends we certainly cannot say anything about a new wave in the future," said Sithabra Sinha, professor at Chennai's Institute of Mathematical Sciences (IMSc).

The reproductive number (R) - the expected number of cases directly generated by one case in a population - for India is at the lowest value it has been since COVID-19 broke here in March 2020, he added.

According to the recent modelling study by researchers at the Indian Institute of Technology-Kanpur, the fourth wave of the COVID-19 pandemic in India may start around June 22 and peak from mid to late August.

The yet-to-be peer-reviewed study, posted on the preprint repository MedRxiv, used a statistical model to make the prediction, finding that the possible new wave will last for four months.

The research led by Sabara Parshad Rajeshbhai, Subhra Sankar Dhar and Shalabh of IIT Kanpur, also noted that there is always a fair chance that a possible new variant of coronavirus may have an intense impact on the whole analysis.

The study led to an animated debate with experts questioning the assumptions made in it.

The precise timing itself is suspect, said Gautam Menon, who has been tracking Covid numbers in India since the beginning of the pandemic. The methodology, in his view, is doubtful and any modelling exercise making predictions months in advance is not trustworthy.

"I would not trust any such prediction, especially one with precise dates and times," the professor, Departments of Physics and Biology, Ashoka University in Haryana, told PTI.