India could witness a third wave of COVID-19 just as a “ripple” if there are no faster-spreading mutations, said projections of the ‘Sutra’ model on Friday. The analysis states that if the virus does mutate, the third wave will be “comparable to the first one”.
The scientists behind the ‘Sutra Model’ were earlier part of an expert government panel set up by the Department of Science and Technology. Three members of this panel came up with the ‘Sutra Model’ last year and have made several mathematical projections on the trajectory of Coronavirus infections. The model is called the ‘Susceptible, Undetected, Tested (positive), and Removed Approach’ (Sutra) to study the trajectory of the pandemic.
Maninder Agarwal, professor, IIT Kanpur, who was among the scientists behind this Sutra analysis, said that they have created three scenarios. First is the ‘optimistic one,’ where the scientists assume that life will go back to normal by August, and there is no new mutant.
Second is the intermediate one, where they assume that vaccination is 20% less effective in addition to optimistic scenario assumptions. In the third pessimistic scenario, scientists assume a new, 25% more infectious variant in August. More infectious than the Delta Plus variant.
As per the Sutra model, if there is an immunity-escape mutant, all the above scenarios will be invalid.
We went through the studies done in the past on loss of immunity and used conservative numbers for them. Similarly, we looked at the projected vaccination rate over next few months, included the effects of vaccine-hesitancy, and arrived at month-wise estimates for vaccination.
— Manindra Agrawal (@agrawalmanindra) July 2, 2021
‘Third wave could be a ripple’
The IIT professor presented a chart to explain the three scenarios. In the graph, the blue curve is the actual COVID data, the orange one is model prediction until May, and the dotted curves are three scenarios plotted from June.
Professor Maninder Agarwal pointed out that there is hardly any difference between optimistic and intermediate scenarios as vaccine efficacy changes do not have a significant impact on the spread of the disease. “A faster-spreading mutant has a bigger impact as shown by the purple curve. Even this is nowhere close to the second wave,” the professor stated.
“So the bottom line is: if there is no significantly faster spreading mutant, the third wave will be a ripple. And if there is such a mutant, the third wave will be comparable to the first one. However, if there is an immunity-escape mutant, all the above scenarios will be invalid!” he added.