The 2023 flu season may be one of Australia's largest flu seasons on record, and doctors are concerned about the impact on children.
Authors
Asha Bowen
Program Head, Telethon Kids Institute
Christopher Blyth
Paediatrician, Infectious Diseases Physician and Clinical Microbiologist, Telethon Kids Institute, The University of Western Australia
You may have seen headlines warning parents about "kindy flu". These can be misleading. This year's flu virus does not "target" children. But during the 2023 flu season, children are particularly vulnerable for one important reason - low vaccination rates.
We are concerned that fewer children have received their annual flu vaccine in 2023, compared to previous years. And it leaves them, and the wider community, at risk of flu and its complications.
How bad is it?
In 2023, we are on track for a similar influenza season to 2019 - the largest influenza season on record in Australia. That's when there were more than 300,000 recorded influenza cases.
At the time of writing, we've had 107,941 recorded flu cases so far in 2023, and the flu season still has months to go. Of these, 48,873 cases have been in children under 15 years and 22,365 in those aged five to nine years.
Since the flu season started in late April, children have made up almost 80% of those admitted to hospital across the country at sentinel surveillance sites. Many children's hospitals are reporting high numbers of children hospitalised with flu.
Sadly, one child has died of influenza, a three year old in Perth.
These large case numbers come after low influenza case numbers seen earlier in the pandemic.
Why is this happening?
The 2023 flu strains do not seem to be any more severe than in other years, according to a number of measures.
In hospitals, the number of those admitted directly to intensive care (currently 7%) is similar to previous seasons.
In the community, the number of those with flu-like illnesses needing to take time off regular duties is also similar.
There is also no evidence the current strains circulating are more likely to infect children, or for them to infect others, compared with strains circulating in previous years.
So something else must be going on.
So what's different in 2023?
The single thing different to pre-pandemic years is the number of younger Australians not getting an influenza vaccine.
In 2020, at this stage of the season, nearly 40% of children aged from six months to under five years were vaccinated, compared with just 20% currently. In those aged five to under 15 years, 25% were vaccinated in 2020 compared with just 12% now.
This makes us worried.
Young children, particularly those under five years, are the group most likely to be hospitalised with flu.
Although children with underlying medical conditions - including chronic disorders of the heart, lungs, nervous and immune system - are most susceptible, more than half of children admitted to hospital each year with flu are otherwise healthy. While rare, flu deaths also occur in previously healthy children.
We are also worried about influenza making children more vulnerable to secondary bacterial infections. These include invasive group A streptococcus and pneumococccal disease.
Another reason to get vaccinated
Children have large volumes of virus in their nasal secretions and, after infection, shed this for days. They also have poorer hygiene practices, often coughing and spluttering over those closest to them.
So children will quickly infect their parents, grandparents and younger siblings. Some will be at higher risk of getting unwell and being hospitalised, such as the elderly, the very young, First Nations people, and those with underlying medical issues including heart, lung, kidney and immune problems.
Primary school-age children are the group that most frequently transmits flu in the community. In 2023, we expect the largest number of cases in the community to be in five to nine-year-olds.
When to seek medical attention
Flu in children commonly causes high temperatures, sore throats, miserable kids and a non-stop runny nose and cough. Most cases can be safely managed at home.
But if you're worried about your child during the flu season, seek medical advice, particularly if your child:
has difficulty breathing (breathing rapidly or drawing in chest or neck muscles)
is vomiting and refusing to drink
is more sleepy than normal
has pain that doesn't get better with simple pain relief medication.
And right now, before they get sick, book in your children for their annual flu vaccine. It prevents more than half of flu infections. And even if infected, vaccinated children are less likely to be hospitalised with it.
Asha Bowen receives funding from National Health and Medical Research Council of Australia, and Medical Research Futures Fund of Australia.
Christopher Blyth receives funding from the National Health and Medical Research Council of Australia, and Medical Research Futures Fund of Australia. He is a member of the COVID-19 Vaccines and Treatments for Australia - Science and Industry Technical Advisory Group and past member of the Australian Technical Advisory Group on Immunisation.
