Doctors have raised concerns about the lack of a vaccine available for young people.

The comments come as a 15-year-old who had tested positive to COVID-19 died in a Sydney hospital. He was the youngest person in Australia to die with the virus.

Osama Suduh died after contracting pneumococcal meningitis and while he also had COVID-19, it was not the reason for his admission to hospital or cause of death.

He was too young to receive a COVID-19 vaccination.

The Australian Medical Association's Danielle McMullen said the teenager's death highlighted concerns around the transmission of COVID-19 among young people.

"We've been concerned throughout this Delta outbreak by the increased rates of COVID-19 in children and young people," Dr McMullen told AAP.

"Given we don't have a vaccine for children under 12, our only way to keep them safe is to stay home and get these numbers turned around.

"In children usually COVID-19 is a mild illness, but we can see some children get really unwell or suffer longer term consequences of their COVID illness."

Western NSW Local Health District chief executive Scott McLachlan said many of the new cases in Dubbo were children.

"We've got nearly 40 per cent of the cases are kids between 10 and 19, so this is a really serious warning for parents and kids running around," Mr McLachlan said on Monday.

There have been 2400 cases of COVID-19 in people aged under 20 in NSW since July 1, with 1488 in the past fortnight.

Mr McLachlan urged children from 12 and above to get immunised against COVID-19.

"We are very keen to see kids ... get vaccinated, particularly Aboriginal kids above 12 years old in Dubbo and the surrounds, vaccines of Pfizer is available," he said.

Dr McMullen says the situation in Dubbo, where there are currently 91 active COVID cases, is particularly worrying.

"The situation in Dubbo remains a real concern, not least with the number of staff being stood down to isolate ... our regional workforce just doesn't have the capacity for the extra workload that COVID presents, like we do in the bigger centres," she told AAP.

Dr McMullen said she had received reports from GPs all over the state concerned by the COVID-19 situation, and that the hospital system in NSW was under strain.

On Monday, NSW recorded its highest case numbers this outbreak with 478 new cases and eight deaths.

A total of 391 people are being treated in NSW hospitals, with 66 in intensive care and 28 on ventilators.

"We've got major Sydney hospitals that have had to convert significant parts of the hospital into COVID care. We have plenty of ventilators, and lots of ICU beds, but the real stress point at the moment is staffing," said Dr McMullen.

She also urged people experiencing symptoms to seek medical help.

"The last thing we want is people staying home with chest pain or other serious symptoms for fear of overloading the hospital system."

The AMA estimates around 70 to 80 per cent of hospital doctors have been vaccinated for COVID-19 so far.