An Assessment of the Health and Economic Outcomes of the Advisory Committee on Immunization Practices (ACIP) Recommended Adult Immunization Schedule (A-IS) Across US States and within Low-Income Populations

Background: State-level aggregate health and economic outcomes associated with the A-IS recommended by ACIP have not been studied previously.

Objectives: Use a mathematical model to investigate health and economic outcomes associated with the ACIP‑recommended A-IS compared with no vaccination in each of the United States and for Medicaid-eligible populations under new health care reform provisions (<130% of the Federal Poverty Level - FPL).

Methods: A cross-sectional, newly-eligible population analysis was performed in which adults (age 18+ years) were assumed to receive vaccinations as they became eligible based on ACIP guidelines. Incremental per-person estimates of discounted costs (updated to 2009$), quality-adjusted life-years (QALYs), and undiscounted disease cases avoided for target vaccinations versus no vaccination were derived from published cost-effectiveness studies. Outcomes were summed within each state and for the adults with income <130% FPL according to the age-distribution within the target population.

Results: Appropriate A-IS vaccination of newly-eligible adults with the lowest income, compared with no vaccination, would potentially prevent 51,400 lifetime hospitalizations across all states. In absolute terms California, the most populous state, would benefit most from A-IS but would also be the most costly.  Compared with no vaccination, the adult vaccination schedule was economically favorable in each state with incremental costs per 100,000 persons at or below $2.33 million for all adults, and $2.73 million for adults with income <130% FPL. Incremental QALYs gained per 100,000 persons were estimated at or below 290 for all adults and 330 for those with income <130% FPL.  The A-IS was most economically favorable in Florida, the state with the oldest population, with minimal variation across states.

Conclusions: Implementing adult immunization according to the current ACIP schedule has the potential to substantially reduce disease burden across all states and to be economically favorable. States with relatively large populations and states with relatively older populations would benefit the most.