Healthcare utilization and costs following RSV and influenza vaccination in older adults in the United States

OBJECTIVE: To compare healthcare utilization and costs in RSV- and influenza-vaccinated vs unvaccinated and influenza-only vaccinated older, US adults in 2023. METHODS: We used a retrospective, cohort study design and the Humana Healthcare Research database to identify individuals enrolled in a Medicare Advantage Prescription drug plan who received RSV vaccination from August 1, 2023 to December 31, 2023. Six-month follow-up through June 30, 2024 was indexed hierarchically on RSV vaccination, influenza vaccination (adults without RSV vaccination), or a primary care visit (adults without RSV and influenza vaccination). We used propensity score matching to adjust for baseline differences and generalized linear regression models to estimate difference-in-difference measures of all-cause inpatient stays, ED visits, outpatient visits, and healthcare costs in the 6 months following index compared with the 12-month baseline period. RESULTS: < 0.001 level. CONCLUSIONS: At 6 months following RSV and influenza vaccination, there is a reduction in medical costs due to fewer inpatient stays and ED visits. This finding highlights the clinical and economic value of vaccination programs for reducing healthcare system burden and improving population health outcomes.