Temporal trends and sociodemographic differences in influenza vaccination among U.S. cancer survivors, 2005-2024.

1674 Background: Given the increased risk of complications and adverse outcomes associated with influenza infection among individuals with cancer, even in the post-treatment setting, clinical oncology guidelines support annual vaccination in cancer survivors. Few studies have investigated long-term trends and potential disparities in the prevalence of influenza vaccination among individuals with a history of cancer. Therefore, we examined temporal trends in and factors associated with influenza vaccination in a nationally representative sample of cancer survivors in the United States. Methods: Using data from 20 survey years (2005-2024) of the National Health Interview Survey, we included adults aged ≥18 years with a self-reported history of cancer and complete data on influenza vaccination. The primary outcome was self-reported influenza vaccination in the past 12 months. Crude annual prevalence estimates were calculated overall and by select sociodemographic characteristics using survey-weighted logistic regression models. Temporal trends were quantified using annual percent change (APC) estimates. Results: Among 43,932 adults with a history of cancer (median age: 65.7 years), representing approximately 15.0 million U.S. cancer survivors annually, crude influenza vaccination prevalence increased from 45.5% (95% CI: 43.0-48.1) in 2005 to 63.3% (95% CI: 61.2-65.4) in 2024, corresponding to an absolute change of 17.8 percentage points (pp; 95% CI: 14.5-21.1) and an APC of +0.79 pp/year (95% CI: 0.52-1.06). Younger survivors aged 18-44 years experienced a particularly large absolute change over the 20-year study period (+32.4 pp; APC: +1.32 pp/year), yet fewer than half were vaccinated in 2024 (46.4%), compared to 77.4% of those aged ≥75 years. Cancer survivors without insurance (change: +24.7 pp; APC: +0.83 pp/year) had a 2024 vaccination prevalence of 32.0%, compared to insured survivors (63.8%). Survivors without a usual source of care (change: +31.0 pp; APC: +1.63 pp/year) had a 2024 vaccination prevalence of 39.9%, compared to those with a usual source of care (63.8%). Hispanic survivors (change: +25.3 pp; APC: +1.30 pp/year) had a 2024 vaccination prevalence of 51.9%, compared to non-Hispanic White survivors (64.9%). Conclusions: Influenza vaccination prevalence among U.S. cancer survivors increased substantially over the past two decades; however, more than one-third were unvaccinated in 2024. Despite overall gains, vaccination coverage remained particularly low among younger survivors, uninsured individuals, and those without a usual source of care, with persistent differences across racial and ethnic groups. Targeted clinical and public health strategies are needed to address these gaps and improve guideline-endorsed uptake of seasonal influenza vaccination among cancer survivors.