Immunity, behaviour, vaccine coverage will determine third Covid wave

Express News Service
BENGALURU: While there is much speculation about the timing and magnitude of the third wave in Karnataka, experts believe that waning immunity, emergence of a more transmissible variant, people’s behaviour during the lockdown relaxations, and vaccination coverage will decide the severity and arrival of the third wave. 

“Karnataka is seeing a reduction in the number of Covid-19 cases, with most of the districts reporting single-digit cases. But the daily new infections are still not beyond the expected mark. The numbers continue to remain in four digits, indicating no sharp decline. At this time, there are a few factors which will decide not just the third wave but future waves too,” explained Dr Manjunath CN, Director of Jayadeva Institute of Cardiology, and member, Covid-19 Technical Advisory Committee.

Interestingly, senior epidemiologists explain that even those who have seen infections in the first wave could be reinfected in the third wave, if their immunity has waned. “The festive season begins in August.

While the third wave is predicted around the same time, people who were exposed to Covid-19 in the first wave would also show a significant waning of antibodies by then. Current data suggests they would still get infected, but would be protected from severe disease, hospitalisation and mortality,” explains a senior doctor from the TAC. 

Experts who have been observing the rise and fall of Covid cases, say it is the nature of the virus to mutate, and the mutation happens faster when the number of cases is high. So the main factor for the arrival of the third wave would be complacency among people, which can lead to a high number of cases, and hence, mutations and arrival of new variants.

“All these are interconnected. A virus mutating and becoming more infectious is not in our control. But if we don’t allow the virus to replicate in our body, the mutations can definitely be avoided, for which we need to control human behaviour. By following Covid-appropriate behaviour, one can stop these waves altogether. There was an induced, forced control introduced in the form of a lockdown, and a second wave was controlled,” Dr Vishal Rao, Dean, Centre for Academic Research, HCG Hospitals, and member of Genome Sequencing Committee, explained. 

Dr Manjunath says that at no cost should superspreader events be allowed, and enforcement of appropriate Covid-19 behaviour should be the government’s focus. As far as variants are concerned, India and even Karnataka have so far seen two highly infectious variants — Alpha and Delta.  

“Between early March and end of May, Delta became the dominant variant. The third wave will also be dominated by the same variant, more or less. But if there is a new mutation with high transmissibility, then the third wave could be much more severe than the second wave,” explained Dr Rao.

Meanwhile, doctors point out that vaccination has to be strictly speeded up to ensure that hospitalisation and mortality is low and lessens the burden on the healthcare system, and warn that the situation can be similar or worse than the second wave.