Rohit Shishodia

As India is yet to get out of the ravages triggered by Covid-19’s second wave, the possibility of a third wave of the deadly disease is looming large. The first wave, which largely infected and killed elders with comorbidities, the second wave of Covid proved deadlier for youngsters and infected those with better immunity.

It may be noted that the new delta variant has resulted in a second wave across states due to which the country saw around two lakh Covid deaths and millions of cases of coronavirus from March to May 2021. This variant is deadlier than the earlier variants. It spreads fast and has a higher infectivity rate. The mortality has also been found high in this variant.

Now amid these concerns, the discussion about the third wave is doing rounds in news reports, social media platforms and even in the public domain. There is a fear in public that the third wave could be more deadly and could cause massive human loss.

However, it is not clear whether a third will come, when it will come and who will be the most vulnerable to it. A lot is being talked about the third wave.

It is being assumed that it will largely infect children while some say that children have already been infected in the first and second wave and possibility of strong third wave is very low. Some experts point out that children have better immunity and they will have mild symptoms even if a third wave comes.

Any prediction about Covid is not easy as the disease is still one and half years old and a lot of research is going on. Mutation, vaccination and people's behavior determine the fate of any wave. DTMT spoke to experts and tried to get insights of the possibility and apprehensions of the third Covid wave.

Dr Sanjay K Rai, Professor, Department of Community Medicine, Delhi-AIIMS, emphasized that any wave depends on agent, host and environment. If there is a large vulnerable population, then any wave can come. Sero surveys can determine this. Sero surveys can ascertain how much infection has spread in the country.

“If we look at the nationwide sero survey that was done in January 2021, around 24% people had been exposed to coronavirus. Some 27% children were found to be having been exposed to the virus, as per this sero survey. What I mean to say is that children were equally infected and had mild diseases. Hence, there is no scientific evidence that a third will come and infect children,” asserted Dr Rai.

Dr Rai pointed out that any wave can come but it depends on availability of host and agents. Now hosts are slowly decreasing. Decline in cases in Delhi, Mumbai and Pune are examples of it. Cases have come down below 500 in Delhi. This means the pool of susceptible population is decreasing, he added.

The other factor is that many people have natural infection and virus is found not upgrading itself in them. Then even if a third wave comes it will not be a big one.

“Now another factor is the agent. If the agent changes so much that it bypasses the natural infection, it can bypass any vaccine too. Then the entire population will be susceptible and no vaccine will work against it. Considering all these factors, there would not be a third. It will only come when a new strain comes,” emphasized Dr Rai.

On the current Covid situation in the country, Dr Rai pointed out that if some areas of North East are left, there is decline of Covid cases in the remaining parts of the country. It is expected that from now cases will continue to decline.

Dr Jugal Kishore, Director-Head, Department of Community Medicine, Safdarjung Hospital, Delhi, said, “There are 15%-20% people who may get the infection in the third wave if it comes. This wave will not be so big it will be a small wave. I don’t think it should be called a big wave.”

“The third wave could be only possible if a new mutant comes and infects those who are yet to get the infection. And another situation is that that variant infects everyone including those who have earlier been infected with Covid. It depends on the possibility of the variant and how infectious that variant is,” he explained.

Speaking about the other countries reporting spikes and waves of Covid, Dr Kishore stressed that it is not necessary if one country has a wave that will also happen in another country.

“If we look at the conditions of other countries, every country has its own curve of coronavirus. Countries may have a spike of the virus like in Delhi but it depends on the behavior of the population. The spike comes if people go outside their homes and forego covid protocols and staying indoors in confines of four walls of their homes is the best option,” he explained.

“Spike can come If people are not vaccinated. It also depends on mutation of the virus. There are many factors behind any wave or spike. Variants, characteristics of population and immunity are major factors that determine waves,” opined Dr Kishore.

He informed that in India in some places 80% of the population might have got the infection and in other places it might be 60%. Some places it will be 50% like in rural areas.

Dr Punit Mishra, Professor, Department of Community, Delhi-AIIMS, echoed the views of Dr Kishore and Dr Rai.

Dr Mishra pointed out, “The data indicates that a good amount of the population in the country has got the infection. Many people have also got vaccines. Hence, there would not be severe waves in future. Unless a big mutation happens, there will not be a third wave.”