How severe is this year’s flu season likely to be?

There have been some alarming headlines about the forthcoming influenza season already this year.
 
A number of publications have reported the country as registering 100 times more flu cases in January and February this year than during the same time in 2022.
 
While technically correct – there have been 8453 cases recorded in the National Notifiable Disease Surveillance System during the first two months of this year, compared to 79 cases in the same period in 2022 – the figures may not tell the whole story.
 
Certainly, Professor Ian Barr, Deputy Director of the World Health Organization Collaborating Centre for Reference and Research on Influenza at the Doherty Institute, is not suggesting that initial data presents for any more cause for concern than is standard – at least, not yet.
 
He has said increased testing rates and more international travel help explain the spike and does not see any clear signs yet that the virus is likely to circulate with any more virulence than in 2022.

‘Cases are still at background levels of activity so there is no indication of an early season like we had last year,’ Professor Barr told newsGP.

‘It is unsure if it will be completely back to normal seasonality (peaking in the first few weeks of August), or it might be earlier.’

There were 225,332 notifications of laboratory-confirmed influenza, and 308 flu-related deaths in 2022, according to the Department of Health and Aged Care (DOH), with notifications declining notably from July onwards.
 
The DoH categorised the clinical severity of the 2022 influenza season as ‘low’ – although not as low as the previous year when influenza had effectively disappeared due to border closures.  

Professor Barr also noted that younger children from six months–five years are included in the National Immunisation Program (NIP) for the first time and said that it is important to attempt to increase vaccination coverage among the cohort.

‘That is definitely worth emphasising,’ he said.

Professor Paul Kelly, Australia’s Chief Medical Officer, stated last month that he is ‘particularly concerned’ about influenza in the youngest age group.
 
‘Last year, children aged younger than five years had the highest influenza notification rates, with only 32% of the cohort receiving a vaccine,’ he wrote to vaccination providers.
 
‘This rate was even lower for First Nations children at 21.5%. Increasing uptake of influenza vaccines should be a priority.’

Supplies for the NIP are due to come online in April, although some private supplies are already in stock.

For Dr Kerry Hancock, Chair of RACGP Specific Interests Respiratory Medicine, lessons learned during the pandemic could also help protect patients along with vaccinations at a time when circulation of respiratory viruses such as influenza are on the rise.

‘In the early pandemic times there were significantly less asthma exacerbations in children and adults, as well as less COPD exacerbations in adults,’ she told newsGP.
 
‘This highlights the importance of the community wide public health measures such as mask-wearing, social distancing, restrictions on social gatherings, handwashing, and working from home to prevent the spread of viral infection.
 
‘Family gatherings with young children drive asthma and COPD exacerbations in adults, with younger children more likely to transmit viral infections to others.’

Professor Barr also said that face masks, preferably the N95/P2 type, should be used as a matter of course in general practice settings.

He said it is worth emphasising the advantage of requesting a respiratory multiplex test, which covers a range of viruses such as SARS-CoV-2, influenza A/B and RSV, instead of asking for standalone influenza or COVID-19 tests.

By doing so, he said it would help form a clearer picture of the main respiratory illnesses in the community.

Professor Barr also highlighted the value of considering influenza antiviral options, such as Tamiflu or Relenza, which he said are most effective if taken within 48 hours after symptom onset.

While he remains unsure at this point about the exact shape of the season, Professor Barr is unequivocal that the circumstances of the early pandemic years are unlikely to be repeated.
 
‘One thing for certain is that there will be an influenza season, unlike 2020 and 2021 when COVID-19 and its many restrictions severely affected influenza circulation,’ he recently wrote in a blog for the Doherty Institute.
 
‘In 2022, influenza returned with a vengeance and will again circulate widely in 2023.’
 
Influenza vaccines are recommended for everyone aged over six months and funded under the NIP for the following groups:

• people aged 65 years and older
• children aged between six months and five years
• pregnant women
• people aged six months and older with medical conditions that increase their risk of influenza
• Aboriginal and Torres Strait Islander people aged six months and older.

flu influenza National Immunisation Program vaccination