Seasonal influenza challenges the notion that only death and taxes are certain. Each fall and winter, those of us living in temperate climates gear up for influenza season, an annual inevitability that imposes a significant public health burden through illness, hospitalization, and death.1 Even the global implementation of COVID-19 nonpharmaceutical measures only temporarily blunted the impact of influenza. By the 2021 to 2022 season,2 we began to see the return of disease activity. Particularly severe influenza seasons, especially among children, followed in 2022 to 20233 and 2023 to 2024, with 187 and 210 pediatric deaths reported in the United States,4 respectively. Notably, severe influenza extends beyond familiar respiratory complications, potentially affecting other organ systems, as well. Children can experience neurologic complications,5 such as the recently reported influenza-associated acute necrotizing encephalopathy. These individual and community impacts underscore the importance of our best protection against influenza complications: the annual influenza vaccine.Given the influenza virus’s tendency to mutate, the composition of the annual influenza vaccine is carefully determined each year through a rigorous global review process.6 Influenza virus vaccine candidates are selected from samples collected from people around the world. Data are presented twice a year, once for the Northern Hemisphere and once for the Southern Hemisphere, and a committee of experts from the World Health Organization issues vaccine virus recommendations. Individual countries then make their own decisions on vaccine virus selection based on what is anticipated for the upcoming influenza season. Vaccine effectiveness (VE) varies from year to year depending on vaccine, viral, and host factors. Influenza VE studies are undertaken to analyze these annual variations. Even within a year, influenza VE estimates may differ between studies because of location, clinical outcome measures, and populations observed.In this issue of Pediatrics, 2 pediatric influenza VE studies, one in the United States7 and one in Europe,8 evaluate the effectiveness of influenza vaccines in the years immediately following the height of the COVID-19 pandemic. In Europe, the study was conducted by the I-MOVE primary care network9 as part of the Vaccine Effectiveness, Burden and Impact studies.10 It included children aged younger than 18 years who attended primary care visits at study sites across 9 different countries in 2022 to 2023 and 2023 to 2024. The US-based study was led by the New Vaccine Surveillance Network (NVSN),11 a network of 7 pediatric medical centers across the country and included children aged 6 months to 17 years seeking outpatient care or hospitalization during the 2021 to 2022, 2022 to 2023, and 2023 to 2024 influenza seasons. Importantly, although annual influenza vaccine is recommended for all people aged at least 6 months in the United States,12–14 influenza vaccine recommendations in Europe vary by country,15 with an increasing number of countries making age-based recommendations for children, regardless of a child’s comorbidities. Both studies published in the United States and Europe use test-negative methodology, which is a type of modified case-control study, to provide yearly estimates of influenza vaccine protection. Ultimately, VE is a comparison of the odds of influenza vaccination in people testing positive for influenza (cases) to the odds of influenza vaccination in those testing negative for influenza (controls) and is represented as a percentage calculated as one minus the adjusted odds ratio times 100%. As in these 2 studies, influenza VE is evaluated against specific medical outcomes, such as outpatient visits or hospital admission.Across multiple seasons, influenza vaccination was found to offer notable protection against outpatient visits7,8 and hospitalizations7 in children, with differences seen by study location, season, age-group, influenza type, and health care setting. During the 2022 to 2023 season, influenza VE estimates against pediatric outpatient visits were 68% (95% CI, 59–76) in Europe8 and 48% (95% CI, 35–59) in the United States.7 In the following season, influenza VE estimates in the outpatient setting were higher, at 71% (95% CI, 62–78) in Europe and 56% (95% CI, 49–62) in the United States. Olson et al also analyzed VE against influenza-associated hospitalization, which was 56% (95% CI, 37–69) and 67% (95% CI, 56–75) in the 2022 to 2023 and 2023 to 2024 seasons, respectively. Predictably, estimates of influenza VE during the 2021 to 2022 season were much lower than in other seasons, likely because of the limited number of influenza virus isolates from the 2020 to 2021 season needed to inform the 2021 to 2022 vaccine formulation. This highlights the importance of the annual influenza vaccine candidate selection process.Despite the clear protective benefits of vaccination, uptake of the influenza vaccine remains low, with only 49% of children receiving the 2024 to 2025 vaccine.16 This represents a 4.2% drop from the previous year and a 13.2% decline from pre-pandemic rates, far short of the Healthy People 2030 goal of 70% coverage among all populations.16,17 The gap between demonstrated vaccine benefits and actual uptake underscores the need to assess how we frame and deliver messages about influenza vaccine effectiveness, especially as lower vaccine uptake may accompany lower perceived effectiveness of the influenza vaccine.18 These perceptions are shaped, in part, by how public health messages are understood. Messaging may come across as overpromising, if not misleading, when patients and families hold fundamentally different understandings of what “effective” or “protective” mean. For many, these terms imply that vaccination will prevent infection entirely. When children still get sick after vaccination, this mismatch between expectations and experience may feel like a breach of trust, compounding the effects of rampant misinformation and post-COVID messaging fatigue.Health communication often falls short when conveying that vaccines work in different ways, leading to confusion and misperceptions about benefits. Some vaccines, such as the measles-mumps-rubella (MMR) vaccine, provide durable immunity: 2 doses are approximately 97% effective at preventing measles infection, and protection generally lasts a lifetime. People who are fully vaccinated are not only far less likely to experience severe disease but are also unlikely to become infected in the first place. In contrast, influenza vaccines are not intended to prevent every infection, but to reduce the risk of outpatient clinic visits, hospitalizations, and death. Not communicating these differences clearly can lead to misplaced expectations and erosion of public trust when vaccines perform exactly as designed but not as presumed.As distrust in vaccines grows, so too does the duty of public health and health care professionals to respond to misperceptions about the benefits of influenza vaccination. So how can we improve communication around influenza vaccine benefits? How do we shift from talking about influenza VE to the protective benefits of a flu shot? It is critical to consider strategies that address people’s real-world concerns, experiences, and expectations. In public health, this is where risk communication comes into play,19 empowering people who are at risk to make informed decisions and take protective action. Principles of risk communication suggest that a primary strategy for engaging people on a high-urgency health topic is to show empathy and not dismiss emotional reactions.20 Demonstrating understanding of parents’ frustration and even exasperation when their vaccinated child still catches the flu builds trust and credibility.Although the flu shot is both “safe and effective,” we should move away from our default assurances and adopt a more candid and forthright approach. This means being upfront with patients and families that flu shots may not prevent infection, while emphasizing its benefits: decreasing severity of symptoms, shortening the duration of illness, reducing the chance of hospitalization, and minimizing household transmission. Framing these benefits around the direct protection of a child and family, rather than emphasizing collective benefits, may better encourage uptake than appeals to the common good.21–23 In a study assessing the Centers for Disease Control and Prevention’s recent “Wild to Mild” flu shot campaign, parent participants found that calling out the attenuation of illness was the most effective messaging and aligned with their own beliefs about flu shots.24 We also need to think beyond the same recycled campaigns year after year. In an age of social media scrolling and a monoculture of public service graphics, vaccine promotion requires distinctive and emotionally compelling content.Our county health department has found success in reaching families by varying our flu shot messaging to include humor and pop culture references. For example, a parody short video, “The Public Health Golden Bachelor,” promoted flu, COVID, and respiratory syncytial virus vaccination to older adults and garnered over 160 000 views and 19 000 interactions on Instagram—over 4000% higher than our typical Instagram posts.25 Routinely refreshed communications that explain the kinds of protection that flu shot offers—including the limitations—may be most compelling and relatable in storytelling and narrative forms.26 Our health department is moving in this direction, using narratives told through comics and video to convey the outcomes of the flu shot for real people.27Candid and creative messaging is powerful, but insufficient on its own. We must ensure that all families have access to clear, straightforward information about the benefits of flu shots so that they can make informed choices. This entails providing communication in the languages they use in formats that are accessible and creating long-term partnerships with trusted messengers who best know the concerns within their communities.28 Our outreach strategies are strengthened by a robust network of Community Navigators,29 representatives who share culturally responsive, linguistically appropriate information about vaccines and other public health topics with communities most impacted by health disparities. Although health department staff bring technical expertise, Community Navigators bridge gaps in language, culture, and trust, allowing us to connect with communities that might otherwise remain underserved. Health care providers also play a pivotal role in shaping how patients understand and act on information about flu vaccination. Each patient interaction presents an opportunity to communicate transparently and set realistic expectations about vaccine effectiveness, reinforcing the same core messages delivered through public health efforts.The 2 studies published in this edition of Pediatrics showcase public health’s commitment to the methodical work required to produce strong scientific evidence. They add to a large body of research consistently demonstrating the effectiveness of influenza vaccination in preventing severe outcomes. But the real-world value of these findings depends on how they are communicated. We are at a critical juncture that calls for new approaches to help people understand the value of vaccines in preventing serious outcomes, and that is where local health departments and health care providers play an increasingly important role. By communicating transparently while emphasizing protection against severe outcomes, and by sharing this information through trusted messengers and settings, we can help ensure that evidence-based science meaningfully informs families’ decision-making.
Chow et al. (Mon,) studied this question.