What shifting influenza vaccination trends mean in 2025-2026 season

• Early signals indicate continued declines in influenza vaccination uptake and shifts in the timing of when individuals seek testing.
• HealthVerity Marketplace provides broad visibility into vaccination and lab-confirmed cases across pharmacies, providers, hospitals and state registries.
• This coverage enables research and public health teams to assemble  influenza patient cohorts with greater accuracy and completeness, facilitating more informed decision making for the 2025-2026 season.

How declining influenza vaccination rates affect public health

In the 2024–2025 season, influenza vaccination rates declined while researchers simultaneously observed a peak in hospitalizations, leading to a notable impact on the US healthcare system. As the 2025-2026 influenza season begins, it’s expected that this trend will persist with vaccination rates continuing to decline.¹ Identifying effectiveness, assessing safety and defining comparative groups becomes more difficult with a shrinking patient pool thus a greater need exists to accurately define influenza cases. 

The HealthVerity Marketplace model for real-world data (RWD) directly addresses these limitations. By linking disparate data types together, vaccinations captured through the most common channels such as pharmacies, physician office visits, and inpatient settings are all accounted for.² In addition, to augment the capture rate and number of cases, HealthVerity also works with multiple state immunization registries to assemble a more robust and representative patient cohort than would be possible using the traditional channels relied on historically. While many states have mandatory reporting requirements,^3-4 several employer- and community-administered vaccination events also feed into these registries, which helps researchers account for immunizations that fall outside traditional claims and EHR feeds offered by other data providers.

Just as it is essential to distinguish individuals with and without vaccine status, it is equally important to identify those with positive or negative influenza test results throughout the season. While HealthVerity Marketplace includes laboratory data from both Quest and Labcorp, covering the large majority of the outpatient laboratory market, data from inpatient and outpatient laboratory tests are also captured through multiple EMR and hospital chargemaster sources, ensuring in-office testing and the most severe hospitalized cases are also included. Combining these sources allows research and public health teams to define cohorts with greater accuracy by distinguishing vaccinated individuals, those who were tested, and those with confirmed illness.

Trends in influenza immunization and testing that impact study design

As discussed, HealthVerity Marketplace enables researchers to identify a vast majority of the vaccinated US population. However, because this assembly brings together multiple data types that capture different views of patients’ interactions with the healthcare system, researchers can also identify influenza testing rates to better understand the associations between emerging trends.

As such, our investigations of the data show that there was also a consistent decrease in individuals being tested for influenza since the 2022-2023 influenza season (Figure 1).

Figure 1: An observed decrease in those receiving influenza vaccinations and also a decrease in testing performed by labs.

We also examined the difference between early-season vaccinations vs total vaccinations since the 2022-2023 season to assess whether this trend held true, on average, among individuals seeking more timely vaccinations.Early season vaccinations were defined as vaccinations occurring between August 1 and October 15. We found that  a smaller proportion of individuals received early-season vaccinations during the 2024-2025 season compared to the 2022-2023 and 2023-2024 seasons (Table 1). This could be reflective of a response to the expected severity of the season, media coverage, or to overall declining vaccination rates. 

Monitoring when patients receive vaccines is imperative for identifying immunity as the effects of vaccinations take roughly up to two weeks to build, but can also diminish over time. 

Table 1: Early-season vaccinations compared to total vaccinations in HealthVerity Marketplace.

We reviewed the number of individuals captured as vaccinated in each state to show where HealthVerity Marketplace identifies the highest volumes of influenza vaccination activity (Figure 2). This helps teams understand where larger cohorts may be feasible based on the underlying data supply.

Figure 2: The number of individuals captured as vaccinated in each state to illustrate where HealthVerity Marketplace detects the largest volumes of influenza vaccinations in the 2024-2025 season.

The HealthVerity advantage in influenza effectiveness and safety research

By combining a vast amount of disparate data types, capturing data across inpatient, outpatient, emergency, community, and laboratory settings, HealthVerity Marketplace enables researchers to assemble influenza-related patient cohorts with greater accuracy, completeness, and validity than using traditional, historically used data channels only. This results in a more representative sample of individuals in the U.S., offering a more reliable view of vaccination behavior at both a national and state level. 

This level of visibility reduces misclassification, confirms true exposure and enhances both the precision and consistency of effectiveness, safety, comparative and HEOR analyses. All of this combined supports implementation of stronger surveillance models leading to more informed and effective planning for the season ahead.

If you’re looking for vaccine or other data, get a demo of HealthVerity Marketplace - the largest healthcare dataset available.

References 

1. CDC. 2025-2026 respiratory disease season outlook. CFA: Qualitative Assessments. August 26, 2025. https://www.cdc.gov/cfa-qualitative-assessments/php/data-research/season-outlook25-26.html
2. The Marketplace model is winning: key insights from our webinar. June 24, 2025. https://blog.healthverity.com/the-marketplace-model-is-winning-key-insights-from-our-webinar 
3. Petrie JG, Fligiel H, Lamerato L, Martin ET, Monto AS. Agreement between state registry, health record, and self-report of influenza vaccination. Vaccine. 2021;39(38):5341. doi:10.1016/j.vaccine.2021.07.090
4. State by state, what’s your infectious disease rate? March 6, 2024. Accessed November 18, 2025. https://blog.healthverity.com/state-by-state-whats-your-infectious-disease-rate