How serious is the flu and how many people get it?
The flu can be a serious disease. While most people who catch flu will simply feel unwell for a week or two and perhaps need a few days away from work or school, in some cases it can lead to hospitalisation, complications such as heart disease, lung disease, and occasionally even death. To learn about some of the possible symptoms of the flu, see our article WHICH FLU SYMPTOMS SHOULD I CHECK FOR?.
Flu is a notifiable disease, which means doctors must report every case to the Department of Health. The number of notifications varies significantly from year to year. For example, there were about 80,000 laboratory-confirmed cases in the 2016 season, almost 300,000 in the 2019 season, and almost 250,000 in the first 10 months of 2022. The number of hospital admissions also changes from year to year. For example, there were 1,767 hospital admissions in 2016 versus about 4,000 in 2019, and about 1,800 between April and October 2022.
While children aged under 5 and adults aged 65 and older are at greatest risk of hospitalisation, people aged 5-64 can develop serious flu infections as well. For example, more than 25% of Australians aged 50-64 are thought to be at high risk of complications from the flu.
When is the flu season and how long does it last?
Although it is possible to catch flu at any time of the year, you are more likely to catch it in the colder months because the flu virus spreads more easily in cooler, less humid conditions and possibly because people are more likely to crowd indoors in colder weather. The peak flu season in Australia usually starts around April and lasts until October, although this varies each year and may differ from state to state.
Why does the flu virus change?
The flu strains constantly change, often as a result of genetic mutations in the virus. This means the flu vaccine must be updated every year. The Australian Influenza Vaccine Committee uses flu data from around the world to help determine the composition of each year’s flu vaccines.
Who should get the flu vaccine and when?
The Department of Health recommends that everyone aged 6 months and older be vaccinated against the flu every year. Vaccination is an important defence against flu, along with common-sense measures such as washing your hands regularly and staying away from people who are sick.
The timing of the flu shot is important. Annual vaccination should ideally occur before the onset of each influenza season. If you are considering travelling overseas, remember, different countries have their flu season at different times of the year. Talk to your GP or pharmacist about flu vaccines and how you can protect yourself against the flu.