Catherine Conlon: Vaccinating kids against flu is key to avoiding hospital overcrowding 

Uptake rates of the free, nasal spray vaccine remain persistently low, writes Catherine Conlon

Increasing vaccine uptake from the low levels of previous years could be a key component to keeping children, as well as everyone they are in contact with, well this winter. Picture: Getty

The nasal spray flu vaccine is now available for children aged two to 12 free of charge as well as to children aged 13 to 17 who are at high risk of flu. It is widely available for both age groups from GPs and pharmacies across the country.

The HSE is also extending the programme to children in senior infants as well as all children in primary-age special schools.

Availing of this vaccine is one of the best things you can do for your child and your extended family this winter — here’s why:

Last winter saw 1,274 children under the age of 15 hospitalised from a preventable influenza infection, HSE data shows.

In the decade between 2009 and 2019, 41 children died from complications of flu and 183 were admitted to intensive care units.

Despite this, vaccination uptake rates of this free, nasal spray vaccine remain persistently low.

Vaccine rates in children aged two to 17 years, last season 2022-2023 across Ireland, ranged from a low of 6.2% in Donegal to a high of 19.5% in Cork.

Dublin came in a close second at 19.4%, with Limerick at 16.6%, Waterford at 15.2%, and Galway at 14.2%, according to HSE data.

No county had more than one in five children vaccinated against this preventable illness, despite the fact that flu can be dangerous for children.

HSE National Immunisation Office consultant in public health Aparna Keegan said that children are twice as likely to catch flu and can spread flu easily to other children.

“Young children, in particular, are more likely than adults to be very sick from flu. Vaccinating children protects them — and their siblings, parents, grandparents, and those who are vulnerable,” Dr Keegan said.

So, not only are children protected from a nasty illness, once vaccinated, they are less likely to transmit it within the household and the community.

The flu season typically peaks around the Christmas period when families move freely between households of families and friends — at a time when doors and windows are firmly shut against wind and rain — allowing viruses to circulate freely.

What happens during the flu season in Australia can be a predictor of how the season will play out months later in the northern hemisphere. Flu viruses are closely monitored in terms of what is circulating, what age groups are most affected, and how well the vaccines are working.

During the covid-19 pandemic in 2020 and 2021, flu rates plummeted globally, influenced by the changes in behaviour with social distancing, hand hygiene, mask wearing, and restrictions on travel. 

In 2022, the flu season peaked earlier than usual, in June instead of August. Predictably, an earlier peak in the flu season occurred in the northern hemisphere in December 2022, two months earlier than the usual peak pre-pandemic.

This year, the flu season peaked at the end of June in Australia — it is too early to say when the peak in the northern hemisphere will be.

But one thing is clear — human behaviour and how many people get vaccinated can be major predictors of how many people succumb to the virus.

Associate professor of clinical microbiology Eoghan O’Neill and RCSI University of Medicine and Health Sciences senior lecturer Deirdre Fitzgerald Hughes, in an article in The Conversation last month, reported that similar to previous years, the highest number of cases of influenza were in children aged five to nine years, followed by younger and older children.

Virus tracking is important because components of the vaccine must be updated each year so that they provide a good match with the strains causing illness in a given year.

The authors report that 59% of Australia’s circulating strains were type A and about 39% were type B.

Viruses are further divided into subtypes based on two proteins on their surface: Haemagglutinin (H) and neuraminidase (N).

There are several H and N subtypes but A(H1N1) and A(H3N2) are the most common types responsible for seasonal flu in humans.

Circulating influenza viruses change because of regular mutations in the virus genes over time. This makes the H and N proteins highly variable, which may affect our immune response. These changes or “antigenic drift” are why new vaccines are needed each year.

Prof O’Neill and Dr Fitzgerald Hughes state that tracking the effectiveness of vaccines during flu seasons can tell if recommendations for a given year were correct. For example, vaccine effectiveness turned out to be quite low in 2017-2018 at 15%, and this resulted in a flu season with higher than usual rates of infection.

“While it’s still too early to assess match and effectiveness, in Australia of the 2,678 flu virus samples sent to the WHO to date, 98% of influenza A(AH1N1) isolates [samples taken from one person], 84% of influenza A(H3N2) isolates and 99% influenza B isolates had similar antigens to the corresponding components."

This means that early data suggests that the influenza vaccines appear to be a good match to offer protection against both succumbing to and transmitting infection. 

Influenza makes people feel worse than the common cold. For most people it is just a nasty experience but for some it can lead to illnesses that are more serious.

The most common complication is pneumonia. It can also cause ear infections, sinus infections, worsening of conditions such as bronchitis, asthma, or heart failure and, rarely, acute encephalopathy (swelling of the brain).

These illnesses can be life threatening especially in those over 65 years and those with underlying medical conditions. Pregnant women are also at increased risk of the complications of influenza.

Research by the HSE Health Protection and Surveillance Centre estimates that influenza can cause between 400 and 800 excess deaths in Ireland every year and up to 1,200 excess deaths in a severe flu season. 

It can increase the risk of heart attacks and strokes.

Influenza is highly infectious and those who are infected can spread the disease from day one before they have symptoms and for five to seven days after developing symptoms. The virus can live on a hard surface for up to 24 hours.

This year, increasing vaccine uptake from the low levels of previous years could be a key component to keeping children, as well as everyone they are in contact with, well this winter. Vaccinating children against flu is a key factor in taking critical pressure off scarce hospital beds.

• Catherine Conlon is a public health doctor in Cork and former director of human health and nutrition, Safefood.