Hyderabad: If there is no significantly faster-spreading mutant of SARS-CoV-2, then the third Covid wave could be just a ripple between October and November. In case there is a fast-spreading mutant, then the third wave will be comparable to the first wave. However, if there is a SARS-CoV-2 mutant that has the ability to escape immunity, then the size of the third wave could be significant, according to the projections on the possibility of a third wave from the SUTRA mathematical model for pandemic.
The SUTRA mathematical model, developed by researchers from IIT-Kanpur, IIT-Hyderabad and Integrated Defence Staff, had earlier quite accurately forecasted the intensity of the first and second waves across the country and even in Telangana.
In the latest SUTRA projections, the group forecasts that if there is no immune-escape variant, then the third wave could happen in the country between October and November. In the absence of a variant that can escape immunity gained by individuals through vaccines and naturally, then the third wave will be far less intense than the second wave.
“We have created three scenarios. One is optimistic one. In this, we assume that life goes back to normal by August, and there is no new mutant. Second is intermediate one. In this, we assume that vaccination is 20 per cent less effective in addition to optimistic scenario assumptions. Third is a pessimistic one. This has one assumption different from the intermediate one which is a new, 25 per cent more infectious mutant spreads in August (it is not Delta Plus, which is not more infectious than delta),” described Manindra Agrawal, the researcher from IIT-Kanpur.
There is hardly any difference between optimistic and intermediate scenarios, suggesting vaccine efficacy changes do not have significant impact. A faster-spreading mutant will have bigger impact but nowhere close to that of the second wave, he said.
Distinguished researcher from IIT-Hyderabad Dr M Vidyasagar said the Delta Plus variant is new but it doesn’t seem to be more infectious than Delta. “At present, Delta Plus is highly localised across the country. While developing the third wave forecasts, we also included possible new mutants in our model,” he clarified.
The SUTRA model developed by Manindra Agrawal of IIT-Kanpur, M Vidyasagar from IIT-Hyderabad and M Kanitkar from Integrated Defence Staff, made spot-on projections of the second Covid wave. The model rightly predicted the second wave would peak in the first week of May and then would start falling in June.