It may not be upon us just yet, but the Australian winter might make it more difficult to fight off COVID-19, according to one of the country’s leading infectious disease experts.

Although flu’s peak time is from June to August, it’s concerning that we’ve already seen the infection spread rapidly while the weather is still warm, says Adelaide University Professor Michael Beard.

“So what’s going to happen in winter? It could be worse,” he told AAP.

“We just don’t know, but there are some concerns.”

One is that the saliva and mucus droplets we cough up and sneeze out are smaller in winter, which means they more deeply penetrate the lungs of anyone who breath them in. It’s not good news if they’re infected.

Mucus is 98 per cent water so it’s instead allowed to dry out, it can produce that crusty kind of nasal obstruction we’re all occasionally familiar with, which also allows pathogens to get trapped in our airways.

One place that has a high likelihood for this to happen is indoors, when heaters are blasting or fires are roaring.

However, when outdoors in the cold, the nose and lungs can have a decreased response to virus infection. So that could be another potential problem.

Professor Beard says perhaps his main concern moving into the Australian Winter is “how this coronavirus is going to interface with influenza virus infection.

“I would urge people to get their flu vaccinations.”

Australian’s have been told that social distancing measures could last as long as two years, with people being forced to stay at home well after Christmas.

Issuing a warning on Friday, Prime Minister Scott Morrison said Aussies can expect six months of stringent social distancing measures as the national infection rate dropped to under 10 per cent.

But infectious disease expert Professor Peter Collignon said COVID-19’s seasonal nature meant the number of cases may not reduce significantly until spring.

“You know what the bad news is? We’re going to have to do a lot of this social distancing for another 18 months to two years,” said Professor Collignon.

“This virus is not going to go anywhere soon. We’ll have a reprieve next spring because there’s less transmission of viruses in summer.”

He added the virus would continue to have an effect in Australia until a cure is found.

This article originally appeared on Over60.