As Australia exits a winter wave, a new frontier is emerging in its battle with the pandemic: the impact of repeated infections and long COVID on its health system and economy.

It remains unclear how many infections develop into long COVID, lingering well after a patient initially contracts the virus, and little is understood about the condition.

But with sufferers often unable to fully function for months, and reinfections climbing across Australia, experts have warned its impacts could be felt for years.

Parliament's health committee on Monday revealed it will launch a probe into reinfections and long COVID, just days after Health Minister Mark Butler announced a $31.5 million splurge on research into the coronavirus.

The committee, set to hear from medical experts and long COVID sufferers, aims to assess the long-term economic, health, and social impact of rising reinfections.

Australian Medical Association president Steve Robson said the condition's impact would prove "difficult to quantify", but data suggests roughly one in eight COVID-19 infections led to long-term symptoms.

The AMA has for months been sounding the alarm over long COVID, and Professor Robson told The Canberra Times he was "extremely encouraged" by Monday's development.

"Now is the time to try to come up with a plan on how to deal with all of this," he said.

"We hope that people who suffer take it as a sign that what they're going through is being taken seriously, and we hope it's the start of something very positive moving forward."

A University of Sydney study in June estimated roughly 5 per cent of COVID patients were still experiencing symptoms three months later, equating to roughly 400,000 Australians.

Professor Robson warned initial research had produced "confusing" but "concerning" results, particularly as an increasing number of Australians test positive for the second or third time.

"It's hard to get longer-term information ... But there certainly is data [showing] that repetitive infection makes it more likely you'll get [long COVID]," he said.

Even those who suffered "trivial" symptoms are still susceptible to developing long COVID, with vaccines offering "a little but not a lot" of protection against the condition, he said.

Predicting the long-term consequences of a new virus was complex, he said, but there was reason to believe they could be severe.

"If you look at herpes, long herpes is Alzheimer's disease. Long Epstein-Barr virus is multiple sclerosis," he said.

"So there are a lot of other worrying models that suggest that long-term effects are not necessarily benign, they can be severe.

"We don't know enough to be blasé at this time."

A Health Department spokesperson said research indicated the Alpha and Delta strains were more likely to produce long COVID, meaning the condition was likely less common in Australia, where Omicron accounted for the vast majority of cases.

Data showed roughly 1 to 5 per cent of COVID-19 infections internationally resulted in symptoms causing "functional limitation" and lasting longer that three months, they said.

"[But] we do not yet have a clear picture on the prevalence of long COVID in Australia," they said.

Committee chairman Mike Freelander, a Labor MP and former pediatrician, conceded a number of question marks hung over the debilitating condition.

"We have a limited understanding of these issues, and it is hoped that this inquiry will build a picture," he said.

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Tae Chung from the US' John Hopkins University, leading international research on the condition, said Dr Chung said agreed that reinfections added extra risk of developing long COVID.

Dr Chung told The Canberra Times the term remains "loosely-defined", given COVID-19 increases the risk of a range of deadly conditions, including lung damage and diabetes.

"One of the most fearful scenarios is autoimmune inflammation," he said.

"Once you have COVID and then you develop [it], you're going be stuck with that inflammation, possibly for the rest of your life."

But long COVID patients typically reported fatigue and brain fog lasting months after their initial infection, Dr Chung said.

That has led some researchers to suspect it is linked to Myalgic Encephalomyelitis/Chronic Fatigue Syndrome, a condition leaving patients bedbound for months and with no known cure.

Submissions to the inquiry will close in mid-November.