The majority of influenza infections occur in children, who are also the primary transmitters of the virus within communities. A comprehensive study involving 29 countries, including Australia, revealed that 19 percent of flu cases were in children under the age of four. A separate study from Hong Kong highlighted that children under 18 were up to 2.8 times more likely to spread the virus than adults, emphasizing the critical role they play in flu transmission.
Children’s propensity to spread the flu is attributed to several factors. They tend to shed more copies of the virus, sometimes even before showing symptoms, and generally have closer contact with adults. Additionally, young children are less likely to wash their hands frequently and are more prone to putting objects in their mouths. According to Professor Kristine Macartney, director of the National Centre for Immunisation Research and Surveillance, this heightened susceptibility is primarily because children are “immune-naive,” lacking the antibodies that adults have developed over time.
The Impact of Influenza on Young Children
While influenza is often perceived as a minor inconvenience for the young and middle-aged, it poses a significant threat to young children and the elderly. In Australia, flu vaccination rates illustrate this perception gap: 60 percent of Australians over 65 have been vaccinated, compared to just 24.7 percent of those under five. Despite this, hospitalization rates for very young children due to influenza are surprisingly high, often surpassing those for seniors.
Professor Macartney stresses the severity of the situation:
“The vast majority of kids we see hospitalised each year are healthy children. When this happens, it is a shock to parents.”
The most recent Australian influenza season report documented 39 flu-related deaths in sentinel hospitals in 2023, nine of which were children.
Vaccination: A Protective Measure
Vaccination remains a critical tool in combating influenza. In Australia, two vaccines are licensed for children under five, administered in two doses. A significant U.S. study in 2020 found that receiving at least one dose of the flu vaccine reduced the likelihood of hospitalization by 55 percent. Professor Robert Booy, an infectious diseases paediatrician at the University of Sydney, notes that while the vaccine’s effectiveness in reducing infections is around 50 to 60 percent, it also contributes to community-wide benefits by reducing virus spread.
Australia has conducted phase 3 trials for one of its licensed vaccines, reporting zero serious adverse events or deaths, reinforcing the vaccine’s safety. Despite these benefits, only 1.1 percent of parents seek medical consultation for their children after vaccination, indicating a low incidence of adverse reactions.
Challenges in Increasing Vaccination Rates
Despite the clear advantages, flu vaccination rates among children have been declining. The COVID-19 pandemic initially prompted parents to vaccinate their children against the flu due to the absence of a COVID vaccine, but this urgency has waned. Jessica Kaufman, head of the vaccine social science team at the Murdoch Children’s Research Institute, explains,
“People were trying to take action against something.”
As COVID-19 receded from immediate concern, the perceived importance of flu vaccination diminished.
Other factors contribute to the decline in vaccination rates. Parents, already burdened with numerous responsibilities, may find it challenging to prioritize flu vaccinations, especially when children are averse to injections. Additionally, the flu vaccine is optional, unlike other childhood vaccines that are more stringently recommended, leading some parents to worry about over-vaccinating their children.
Looking Forward: The Importance of Awareness
The decline in flu vaccination rates among children is a concerning trend that warrants attention. As children are significant vectors for flu transmission, increasing vaccination coverage could substantially reduce the spread of the virus and protect vulnerable populations. Public health campaigns emphasizing the safety and benefits of flu vaccination, coupled with efforts to make vaccinations more accessible, could help reverse this trend.
Ultimately, the decision to vaccinate is a personal one, but informed choices can significantly impact public health. As Professor Macartney cautions,
“We don’t want to see kids with severe illness.”
Raising awareness about the risks of influenza and the protective benefits of vaccination is essential in safeguarding the health of children and the broader community.
