An elderly woman has become the first fatality of a COVID-19 and influenza combination in Australia.

The unvaccinated 90-year-old from Victoria died in January after catching the coronavirus and the flu at the same time, a condition that has been dubbed "flurona," News.com.au reported.

She was among the six people in the state who contracted both respiratory diseases, noted the outlet.

The five other cases, all of whom aged between 16 and 64 years old, were vaccinated for COVID-19, a report by Yahoo News said.

Overall, more than a dozen Australians have been infected with the coronavirus and flu at the same time, as per 7News.com.au.

A recent study in the United Kingdom found that the combination doubles the risk of death compared to a COVID-19 infection.

In addition, flurona also "greatly increases the change of all the serious outcomes" from either COVID-19 or the flu, according to Dr. Paul Griffin, an infectious diseases expert at the University of Queensland.

"[Y]ou’re much more likely to end up in hospital, and much more likely to have those serious consequences," said Griffin.

"And even if you don’t get both together, because our population is very susceptible, the consequences of the flu this year are going to be very significant," he added.

Nadav Davidovitch, the director of the School of Public Health at Ben-Gurion University in Israel, warned in January that people were at risk of catching the combo infection due to the "high activity" of both COVID-19 and influenza.

"I don't think this is going to be a common situation, but that's something to consider," Davidovitch said.

It is reportedly not possible for someone to determine if they have COVID-19, the flu or flurona based on symptoms alone since fever, cough, chills, sore throat, body aches, congestion, runny nose, vomiting and diarrhea are common in all three conditions.

Victoria’s Department of Health has urged people to make sure all of their jabs were up to date ahead of the flu season.

"By getting vaccinated against both highly contagious infections, you’re not only protecting yourself and those around you, but you’re also helping to ease pressure on our health system," a spokesman for the department said.

Australia has reported a total of 6,122,957 COVID-19 cases and 7,424 virus-related deaths, based on data provided by the government.