COVID and influenza are at peak circulation in winter, with several million people in Australia getting ill from these respiratory viruses each year.
In a post-pandemic world, many Australians now think of influenza as the more serious of the winter viruses – but Associate Professor Joel Rhee, Head of Discipline of General Practice at UNSW Sydney, says the national data tell a different story.
"When I ask medical students, 'what do you think is more serious – influenza or COVID-19?' almost 100% say influenza," says A/Prof. Rhee. "But the statistics say otherwise. COVID-19 is still causing more deaths than flu."
COVID's most serious impacts, including hospitalisation and death, remain heavily skewed towards older adults and those with chronic health conditions.
In conducting his clinical work within aged care homes, A/Prof. Rhee sees the impact of the disease firsthand.
But, he says, it also "doesn't seem to be a serious disease in young children, unlike influenza, which can affect all age groups, including infants."
In 2024, the highest rates for influenza were in children under 9 years old.
Protecting yourself, your loved ones (and others)
Respiratory diseases spread when droplets from coughs, sneezes or even the breath of an infected person enter another person's body through their eyes, nose or mouth.
A/Prof. Rhee says vaccination remains the first and most effective line of protection, with influenza being the most common vaccine-preventable disease in Australia.
"It's not too late to get your flu shot," he says. "It does take a couple of weeks to kick in, but once it does it provides about four months of protection – just in time for the typical August and September flu season peak."
A/Prof. Rhee says vaccine recommendations for COVID have evolved post-pandemic.
"We're no longer recommending an annual booster for most healthy people," he says. "But those over 65 or with underlying health conditions may need annual or more frequent boosters."
Healthy people who are caring for vulnerable relatives or who are travelling should also consider a booster, he says.
In addition, common-sense practices in hygiene and self-care help guard against sickness: handwashing, keeping up your fluids, staying away from other sick people and wearing masks in crowded places.
"In packed settings – like on public transport at peak hour – it's perfectly reasonable to wear a mask," A/Prof. Rhee says. "And nowadays, N95 masks are easy to get and more effective than standard ones."
Not a common cold
The immune system includes a combination of B cells (which make antibodies) and T cells (which act directly on the pathogen).
Vaccinations introduce a small amount of a pathogen's protein to the body. This trains the T and B cells to recognise the pathogen – and then build an army to fight it over a lifetime.
While some antiviral medications can help when started soon after infection, if you are hit by a flu-like virus, expect a rough ride – and a potentially long one.
"Influenza leaves you crook as a dog for about a week with fever, aches, no appetite and just feeling wiped," says Professor Andrew Lloyd, an infectious disease physician at the Kirby Institute who also leads the UNSW Fatigue Clinic.
"But for many people, that's just the beginning.
"Lingering symptoms like fatigue, brain fog and sleep disruption can persist for weeks, sometimes months."
New kid, old block
Prof. Lloyd says these prolonged symptoms are typical for what's now termed 'Long COVID' – but his research shows they are not unique to COVID.
"These symptoms also follow glandular fever, Ross River virus and Q fever," he says. "Long COVID has drawn attention to these post-viral fatigue syndromes – but they've always existed.
"They crop up again and again."
What Long COVID has done, he says, is shine a spotlight on post-viral syndromes that have long been under-recognised as a cause of chronic fatigue.
"It's the new kid on the block but it's brought attention – and research – to an old story," Prof. Lloyd says.
He led the landmark Dubbo Infection Outcomes study in regional NSW more than 20 years ago. The study followed about 500 people who were diagnosed with either glandular fever, Epstein-Barr Virus (EBV), Ross River virus or the bacterial infection, Q fever.
The data show around 30% of people with these infections were still experiencing symptoms three months later. A smaller percentage remained unwell at six and even at 12 months.
Prof. Lloyd says what was surprising wasn't how different the acute infections were – but how similar the lingering symptoms were, regardless of the trigger.
"It didn't matter if it started with a sore throat from glandular fever, a rash from Ross River virus, or headache and drenching sweats from Q fever," he says.
"What people were left with was a consistent set of complaints: fatigue, cognitive difficulties – what you might call 'brain fog' – irritability and unrefreshing sleep."
Prof. Lloyd says these symptoms are also characteristic of Long COVID.
He says most people do get better with time. And that careful, structured rehabilitation – not just rest – is the best path forward.
"It's not about complete rest for months – that won't help," Prof. Lloyd says. "It's about rebuilding tolerance to physical and mental activity through graded rehabilitation.
"That's how we manage Long COVID and similar conditions."
The future viral landscape
Prof. Lloyd is currently co-leading a study investigating how today's newer strains of COVID-19 compare to Influenza and Respiratory Syncytial Virus (RSV). He says early signs suggest the Omicron-era infections that appeared towards the end of 2021 may be less likely to result in Long COVID than previous waves.
"We suspect the severity and duration of Long COVID are decreasing," Prof. Lloyd says. "Most people are now vaccinated or have had COVID before, so the immune response is much improved."
The studies in Long COVID aim to identify biomarkers – to offer better diagnostics and treatment for everyone dealing with chronic fatigue.
What if you get COVID?
A/Prof. Rhee says while the pandemic may seem like a distant memory for some, the virus is still going strong – and remains a significant risk for older Australians and those with underlying health conditions.
"COVID-19 is still a significant cause of death in aged care," A/Prof. Rhee says.
He says residents in aged care homes, those with underlying medical conditions and those who are 70 years of age or older should contact their doctor as soon as possible after testing positive to COVID-19. The doctor can then assess whether a course of antiviral medication can help.
According to wastewater surveillance, a new COVID variant is also emerging – and there's no way to predict how it might behave.
"There's no reason to believe our current vaccines won't work against it," A/Prof. Rhee says, "but it's all the more reason to practise good hygiene and test if you have symptoms."
A/Prof. Rhee says anyone who gets sick should inform their family and close contacts, so they can also monitor for symptoms and get tested.
He says rapid antigen tests remain widely accessible – with some GP clinics and aged care facilities offering them for free.
"If we can all take simple steps – getting vaccinated, washing hands after coming home or before eating or drinking, staying home when we're sick, wearing a mask in crowded spaces – we can reduce the virus circulating in the community.
"And that protects everyone."
