How deadly will the third wave of COVID-19 be? Hear it from the scientist

New Delhi, July 04: With the second wave of COVID-19 subsiding, the big question is how deadly is the third wave.

Professor Manindra Agarwal, who is working with the Sutra Model, the mathematical projection of the Covid-19 trajectory says that the the third wave may only see half the daily cases recorded during the second wave.

@stellensatz @Ashutos61 @Sandeep_1966 @shekhar_mande It took us a while to do the analysis for three reasons. First, loss of immunity in recovered population. Second, vaccination induced immunity. Each of these two need to be estimated for future.

— Manindra Agrawal (@agrawalmanindra) July 2, 2021

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% less effective in addition to optimistic scenario assumptions," he said in a tweet.

And third, how to incorporate the two in the model. Fortunately, it turned out that both can be incorporated by suitably changing contact rate and reach parameters. So that takes care of third one. First two required detailed analysis.

— Manindra Agrawal (@agrawalmanindra) July 2, 2021

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 is pessimistic one. This has one assumption different from intermediate one: a new, 25% more infectious mutant spreads in August (it is not delta+, which is not more infectious than delta)," he also said.

Then came imponderables. Will there be a new, more infectious, mutant? If yes, when will it strike? When will people abandon caution completely as in March this year? One can only make guesses, which may be completely wrong. Hence, it is better to compute a few what-if scenarios.

— Manindra Agrawal (@agrawalmanindra) July 2, 2021

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% less effective in addition to optimistic scenario assumptions.

— Manindra Agrawal (@agrawalmanindra) July 2, 2021

Here are plots for the three scenarios. Blue curve is actual data. Orange one is model prediction until May. Dotted curves are three scenarios plotted from June. pic.twitter.com/yDeLnp2rQf

— Manindra Agrawal (@agrawalmanindra) July 2, 2021

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% less effective in addition to optimistic scenario assumptions, he further added.