The pathogen has adopted “hit and run” tactics to breach the immunity many people developed during the first wave as also due to vaccination, Prof Vijay Raghavan said, pointing to changes in the virus and the role of new variants with higher transmissibility and disease severity in the second wave.
“A phase three (of Covid-19 pandemic) is inevitable given the high levels of circulating virus but it is not clear on what timescale this phase three will occur. Hopefully, incrementally but we should prepare for new waves,” Prof Vijay Raghavan said.
The possibility could not be wished away as long as human hosts were available for infection and the only way to reduce this vulnerability was through safe practices and vaccination. “The best time to change our behavior is now,” he said emphasising on the need to adapt Covid-appropriate behavior. “What we do, what we need to do does not change because of the virus. Masks and distancing are critical and most effective,” he said.
Infections and vaccinations are likely to cause “adaptive pressure” on the SARS-COV2 virus, triggering new kind of changes, he said. Scientific studies were on to examine likely alterations to tackle any upsurge in future.
With the government acknowledging the inevitability of a third Covid-19 surge, the planning to deal with it should begin now. The government must prepare for cases exceeding what is anticipated. Advance planning and preparation can help avoid a repetition of the tragic circumstances caused by the second wave. At the same time, rapidly scaling up vaccination and other measures to minimise the spread must go hand in hand.
Explaining why the second wave has been larger and much more severe, Prof Vijay Raghavan said: “Phase 1 was a generalist approach of the virus and phase 2 now has fitter viruses arising due to post-immunity due to previous infection. Variants of concern represent better adaptation and are triggered by human population.”
While assuring that the infections caused by new variants will plateau, the principal scientific advisor cautioned that immune evasive variants and those which lower or increase disease severity will arrive in the future.