Flu, COVID and flurona: what we can and can't expect this winter

When it comes to respiratory viruses, COVID has been our greatest concern over the past two winters. So you might feel some aspects of déjà vu as winter 2022 approaches in Australia.

But this year is different. With relaxed public health measures and the opening of international borders, we will likely see a rise in flu cases. This is on top of a predicted rise in COVID.

The potential double-whammy has prompted the federal government to announce A$2.1 billion to target these expected spikes. The funding has been earmarked for measures including vaccination, testing and measures to protect aged care.

Here's what to expect and how to protect yourself ahead of winter.

Why can we expect more flu?

The main reason behind the expected rise in flu in 2022 is the opening of Australia's international borders.

Tourists and returning residents can arrive without quarantining, provided they have the required COVID vaccinations and have had a COVID test beforehand. However, new arrivals don't have to be tested for the flu virus, which they may inadvertently bring with them.

Flu, a little like COVID, can be spread by infected others before symptoms arise or even if symptoms don't appear, something we regularly see in children. So once flu arrives, it will inevitably spread, regardless of whether we use masks, hand sanitiser or other measures.

In the past two years, for instance, we've seen large outbreaks of other common respiratory viruses. These include respiratory syncytial virus, human metapneumovirus, adenoviruses and rhinovirus. We've seen these even with strict COVID measures in Victoria, New South Wales and Queensland during 2020-2021.

How bad will it get?

It's highly likely we'll see COVID and influenza circulating at the same time this winter. But less certain is the more catastrophic predictions in the media of a so-called twindemic or syndemic.

COVID is more likely to persist and increase during the winter, and sometime during this period influenza will pop up. But we're uncertain about the details.

Will flu be mild or more concerning in 2022? Will we see a rise in cases during the usual June-September period, peaking normally in August? The answers to these questions rely on history, the current situation and a good deal of speculation.

History tells us that after two seasons of low or no influenza circulating, we should expect a more severe season. That's because the majority of people are not vaccinated against influenza each year and peoples' natural immunity after infection will have waned.

However, current evidence argues against this. In the Northern Hemisphere, there have been low levels of flu circulating in most countries, with shorter outbreaks, compared with pre-pandemic years.

We've also seen a number of countries in the Southern Hemisphere - including South Africa, Brazil and Chile - having out-of-season flu outbreaks, during their 2021-2022 summer.

So this may mean the timing of Australia's normal influenza season might be delayed until spring or even later in 2022.

Will I get 'flurona'?

We may also see dual infections - when someone has COVID and influenza at the same time - sometimes dubbed "flurona".

While this has occurred, the rates of dual infections globally have been low. Generally, under 1% of people with COVID also have influenza at the same time. Even with dual infections, people do not seem to be sicker than if they had COVID alone.

We'll have a better idea of how many people will be infected with both viruses at once with the use of broader laboratory tests now available at many sites. These so called multiplex tests will detect a range of respiratory diseases, including COVID and flu, in a single test.

Fortunately, there is no way a new "hybrid virus" can emerge containing parts of SARS-CoV-2 (the virus that causes COVID) and the influenza virus in people with dual infections. These are distinct viruses that cannot combine.

How can I protect myself?

Despite the uncertainties around flu in Australia in 2022, the best way to protect yourself is to get your flu vaccine.

Everyone is susceptible to flu, no matter your age, health or lifestyle. However, some age groups and some people with underlying disease are likely to suffer more severe consequences if infected with influenza.

These include young children (especially those under two years old), people aged 65 and over, pregnant women, people with chronic lung and heart disease, those with asthma, diabetes and people who are obese.

Different flu vaccines target different age groups with different formulations. These vaccines have a proven safety record and usually only cause very mild reactions, such as soreness at the injection site, mild fever or headache. These may last for a 12-24 hours and are easily treated with paracetamol or similar medications.

Flu vaccines are free for children aged six months to under five years of age, people aged 65 or older, pregnant women and all Aboriginal and Torres Strait Islander people six months and older. People not eligible for free vaccines can still get them via their GP or some pharmacies.

This year you won't have to schedule different visits for your influenza and COVID vaccinations. If needed, you can get them at the same time.

Influenza vaccines will be available from late March and will provide protection for at least 6-12 months. While these vaccines are not perfect they help prevent infection and the more serious consequences of the flu, such as hospitalisation and even death. So in April to May this year, as the cool days and nights return, think about booking in and getting your flu shot.

Ian Barr owns shares in a vaccine producing company. His Centre receives funding from the Australian Government Department of Health as well as a number of commercial pharmaceutical companies.