More than a year and half into the pandemic, our understanding of COVID-19 and SARS-CoV2 – the virus that causes it – has changed immensely.

Never before have so many of the world's researchers, given their all to solve the puzzling, ever-changing nature of the virus.

When Covid broke out in China's Wuhan, and gradually spread to other parts of the world, we thought the elderly and those with comorbidites were most at risk.

In fact, there is growing evidence that Covid affects kids differently than adults. There is also an increasing trend in countries with high vaccination rates like the US, the UK and Israel, where a huge chunk of young people are getting infected.

So, does this mean that the narrative around Covid has changed? Has the disease burden shifted to the young? It's a tricky question.

"What the Western world is seeing now, India has already seen this," Dr Suranjit Chatterjee, Senior Consultant, Internal Medicine, Indraprastha Apollo Hospitals, says.

With vaccination picking up in many countries, the absolute number of COVID-19 cases may come down. Does this mean that the share of cases among the unvaccinated – the younger age groups – rises?

Has the pandemic started to look like a disease of the young?

"When we say that COVID-19 is becoming a disease of the young, we have to be very careful with our terminology and recognise there is a difference between susceptibility to infection and predisposition to severe disease outcomes," Dr Swapneil Parikh, Author and Internal Medicine Specialist, says.

It's true that the spread could be driven be younger people. But the question is, relative to adults, what is their risk of infection? What is their capacity to transmit? And what is their risk of disease?

Dr Parikh says that the overall risk of death due to Covid in children remains low compared to the elderly.

So, if a vaccine is 99 percent at preventing death, for an 85-year-old, the infection fatality rate would be around 0.15 percent. Meanwhile, for a 10-year-old, it would be 0.002 percent.

This shows that the risk of death in a child is still lower than that in an elderly person.

While the vast majority of severe cases across the world will still be in the elderly, that doesn’t minimize the suffering of children who do have severe disease, and some do have severe disease, Dr Parikh adds.

Variants might also play a role in driving infections. For example, the highly infectious Delta variant poses a new risk for the unvaccinated children.

It's not just vaccination or the variants which have changed the COVID-19 landscape.

Now that more people are getting the jab, their risk appetite has changed, and that may drive a spike in infections among children, Dr Parikh says.

The crux of the matter is that there has been a shift in the pattern of COVID-19 infection. Our initial perception that children don't get sick is wrong.

Whether COVID-19 has become a disease of the young or not, all these concerns could be critical now that schools are gradually opening up.

While we should protect children, we should also recognise that it’s the elderly and those with pre-existing conditions of all ages who are most vulnerable, Dr Parikh adds.