Before COVID-19 ripped through the population in the summer of 2021, relatively few Australians were acquainted with the term "long COVID".
But when the rate of COVID-19 in the community dramatically increased, and more people reported ongoing symptoms after their infection, long COVID entered the mainstream vernacular.
Judy Li from Melbourne first spoke to the ABC in October 2021 while in the grip of debilitating fatigue and brain fog.
Working as a project manager, she used up all her annual leave and was on unpaid leave.
Her partner was caring for her and their two children, while also trying to meet the demands of his job.
All the while their savings to buy a house took a back seat, and Judy was wracked with guilt for not being able to work or play with her kids.
Nearly a year and a half later, her physical health has somewhat improved, and at the start of 2023, her energy returned.
She was able to get up and organise the kids in the morning, do some gardening outside and help around the house.
Judy is now back at work, albeit in a different role, and works five-hour days across four weekdays.
But she has struggled with her mental health, and the return to work has seen her fatigue flare up again.
"Now I've seen that my body can function better, hopefully it's a dip and [my energy] will go back up, but it's so unpredictable," Judy said.
She and her partner managed to buy a house with help from family, but with mortgage repayments constantly on the rise she cannot afford to take more unpaid leave.
Judy said she has been working with doctors, including a psychiatrist and cardiologist, to help investigate and treat her symptoms.
How has our understanding of long COVID changed?
Long COVID refers to the long-term health and cognitive effects from a COVID-19 infection.
The list of symptoms range in the hundreds, but the most commonly reported are fatigue, shortness of breath and cognitive dysfunction.
The World Health Organization estimates it affects 10 to 20 per cent of people who have a COVID-19 infection, and data from an Australian post-COVID clinic shows it often affects women in their 40s and 50s, most of whom led active lives before they got sick.
But there's still much we don't know.
Anthony Byrne, who leads the long COVID clinic at St Vincent's Hospital in Sydney, said the current consensus of the definition was that patients had to have:
- probable or confirmed SARS-CoV-2 infection
- persistent symptoms for at least 12 weeks, including the acute infection period, that could otherwise not be explained.
Dr Byrne, whose clinic sees patients ranging from 16 to 90 years, said because a lot of the data is self-reported, a doctor must assess if there's any other underlying reason for the symptoms.
"That said, most people who think they have long COVID have long COVID, but the point is: what are the other co-factors or contributing conditions to their long COVID?" he said.
Earlier in the pandemic, data suggested long COVID tended to affect people hospitalised from their initial infection, generally older people, and those who were unvaccinated.
"If you aren't vaccinated, older, went to hospital, then it stands to reason you've got a high chance of long COVID — and that's exactly what the studies show," Dr Byrne said.
But in the past year, he said, it became obvious that long COVID also affects people who were not hospitalised, who were vaccinated, and of different ages.
Having an autoimmune condition or high stress levels can increase the risk too, as can the number of symptoms experienced with the initial COVID-19 infection.
"If it's five or more [symptoms], that increases your risk," Dr Byrne said.
"So if you've got a lot of symptoms initially, it stands to reason that that might take a lot longer to resolve, and that's what we find in the studies."
Medical experts brought in to discuss next steps
As year three of the COVID-19 pandemic rolls around, long COVID patients like Judy are still waiting for answers.
"A lot of the specialists that I've seen, it's been, 'You've got chronic fatigue. There's not much we can do about it,'" she said.
"That's a really hard place to be, you know?"
An inquiry into long COVID and repeated COVID-19 infections is underway in federal parliament.
On Friday, the inquiry invited leading experts to contribute in a roundtable discussion about the next steps for Australia's response.
The discussion, jointly run by the Australian Academy of Science (AAS) and the Australian Academy of Health and Medical Sciences (AAHMS), brought together representatives from areas including infectious diseases, epidemiology, immunology, mental health and public health.
AAS president Chennupati Jagadish said there was still a limited understanding of the prolonged effects of COVID-19.
"The evidence is still evolving. It is crucial we continue Australian research to inform future decision-making and also development of the new policies as well," Professor Jagadish said.
"Also to [find] the knowledge gaps, and how do we make sure that those knowledge gaps are filled by investments into better understanding long COVID?"
Some of the gaps identified by the expert panel included the prevalence of long COVID, who is at risk, adequate research and a sustainable infrastructure for surveilling it, and research networks to help facilitate national studies.
Substantial and strategic funding where research groups are not having to compete against each other was also discussed.
For Dr Byrne, the most pressing knowledge gap was identifying the people at risk of long COVID, as well as upskilling GPs in how to diagnose and manage the condition.
"It shouldn't be something that's esoteric. It should be like diagnosing diabetes," he said.
"I think the priorities are upskilling healthcare professionals because, believe it or not, there are healthcare professionals out there that don't believe in long COVID.
"That's really hard if you're a patient with long COVID."
What's next for Australia?
Australia's chief medical officer Paul Kelly said a national plan is being developed, but won't be finalised until the parliamentary inquiry has wrapped up and the committee has given its advice.
"I think it's fair to say we still have an awful lot to learn about long COVID," AAHMS president Steve Wesselingh said.
"We need to develop a very clear definition of long COVID, then we need to understand what the true incidence and prevalence of COVID is currently."
With so much still unknown about long COVID, he said funding for research was key.
"I think it's very hard to develop a public health response when you actually don't own the size of the problem," he said.
