There are growing fears that the Delta variant of the coronavirus may be more pronounced in younger people after it was revealed a teenager is being treated for COVID-19 in an intensive care unit in New South Wales.

On Saturday, NSW Premier Gladys Berejiklian said officials had seen an unusually high number of young people with severe illness from COVID-19 as the Delta strain ravages the Sydney area.

“We have a number of young people in ICU at the moment and that is a phenomenon we have not seen before,” she said.

The city recorded another 50 cases from more than 42,000 tests, including 37 people who were active in the community for all or part of their infectious period.

It was the worst day of the current virus outbreak, prompting Ms Berejiklian to again warn lockdown was likely to be extended.

The premier conceded that with so many infected people out and about in the community, the situation may “worsen before it gets better”.

There is currently some debate over whether the Delta strain is more severe in younger people, or whether they are simply more likely to become ill because they have not been offered vaccines yet like older age groups.

Preliminary research from the northern hemisphere has found the virus is better at binding to younger people’s cell receptors – which may make it more severe for that demographic.

The Delta strain also moves more quickly than anything we’ve seen before.

Instant infections

At the start of the pandemic, health authorities thought it took about 15 minutes of close contact for someone to become infected with COVID-19. Now they know it can happen almost instantaneously.

Paul Griffin, an associate professor of medicine at the University of Queensland, said there was no denying Delta was more serious.

“The reality of COVID is that it smashed the idea that young people don’t get severely ill from the outset, and Delta hammers it home even more harshly,” Associate Professor Griffin said.

“There is no one that can afford to be complacent. Children, young adults, we all need to be on our toes.”

We are also seeing more young people getting severely ill for one simple reason – they aren’t vaccinated, he said.

“The vaccines work well at preventing severe disease,” Associate Professor Griffin said.

“We’ve focused on the elderly and vulnerable in our rollout, and have protected a proportion of those groups.

“Those younger people [who are not inoculated] are going to see some more severe illnesses.”

The United Kingdom is currently grappling with this crisis.

This week, England’s chief medical officer, Chris Whitty, warned that more young people will get ‘long COVID’ as the Delta variant pushes up infection rates.

“I regret to say I think we will get a significant amount more ‘long COVID’, particularly in the younger ages where the vaccination rates are currently much lower,” Professor Whitty said.

Associate Professor Griffin said the situation in NSW needs to be a wake-up call to the whole nation to take Delta seriously.

“Once again, the vaccine is the solution to the problem,” he said.

“While our supply constraints are dictating how wide our rollout is, we need to be prepared. It’s getting closer and closer. We need to get the messaging right.”

Can NSW get on top of it?

On Saturday, Premier Berejiklian pleaded with residents of Greater Sydney, the Blue Mountains and the Central Coast to comply with the lockdown restrictions, warning the state may otherwise suffer a “prolonged” lockdown.

Epidemiologists have warned the lockdown could stretch for weeks before the virus is contained.

Australian Medical Association vice-president Chris Moy said the likelihood of opening up as planned next Friday (July 16) is low.

“The lesson has been learnt, especially with Delta: going hard, going early works,” Dr Moy said.

“Otherwise you’re going to have much worse medicine for much longer.”

Both the NSW population and the state government need to make sure they are doing lockdown “properly” now, as the impact of lockdown on case numbers won’t be known for another five to seven days, he said.

“Because we don’t have a high enough vaccination rate, our only choice is to lock it out,” Dr Moy said.

“It’ll overwhelm us too quickly. You’ve got to nail it now.”