'Hybrid' immunity, vaccination behind low Covid cases, big 3rd wave unlikely'

New Delhi: Is the worst of the Covid crisis behind India? As cases dip three weeks after Diwali, the answer is a possible yes, say several experts, attributing the downslide to a large section of the population already exposed to the virus during the second wave and a stepped up vaccination campaign.

Though there are always imponderables, including the possibility of a new, transmissible variant and the onset of winter in large parts of the country, a third wave as devastating as the second one is unlikely, they said while advising caution and vigilance.

Covid cases may rise, perhaps across late December-February, but the impact will be milder than what India experienced in the second wave when thousands died and many thousands more were hospitalised.

It may not take off in a coordinated manner across the country, provided no far more transmissible variant comes along, explained Gautam Menon, professor, Departments of Physics and Biology, Ashoka University, in Sonepat.

Several epidemiologists had predicted a third wave peaking in October and November because of large gatherings in the festive season, which includes Durga Puja and Diwali. But the much feared spike thankfully hasn't happened.

On Tuesday, India recorded 7,579 new coronavirus infections, the lowest in 543 days, taking the country's total tally of COVID-19 cases to 3,45,26,480, while active cases were the lowest in 536 days, according to Union Health Ministry data.

The daily rise in new infections has been below 20,000 for 46 straight days and less than 50,000 daily new cases have been reported for 149 consecutive days.

What it suggests is that the impact of the second wave, where a substantial fraction of Indians were infected, continues to manifest itself, Menon told the news agency.

In addition, a stepped-up vaccination campaign has meant that more people are protected against severe disease, hospitalisation, and death, he added.

In his view, the substantial number of people infected during the second wave from March to July this year is the prime protective feature at the moment for India, while vaccines add to that protection .

A combination of a prior infection with a later vaccination may be even more protective than just the vaccination alone, said Menon.

Many scientific studies suggest that people who become naturally infected with Covid and recover before vaccination develop hybrid immunity , better immunity than those who only have antibodies from vaccination.