Cost-effectiveness of recombinant influenza vaccine compared with standard dose influenza vaccine in adults 18–64 years of age

Abstract

BackgroundThe Advisory Committee on Immunization Practices (ACIP) uses the Evidence to Recommendations Framework that includes cost-effectiveness analyses (CEA) for determining vaccine recommendations. ACIP’s preference for protecting adults ≥ 65 years is enhanced vaccines, including recombinant influenza vaccine (RIV4), adjuvanted or high dose influenza vaccine. Less is known about the CEA of enhanced vaccines for younger adults. MethodsWe used decision analysis modeling from a societal perspective to determine the cost-effectiveness, measured in quality adjusted life years (QALYs), of RIV4 compared with standard dose quadrivalent influenza vaccine (SD-IIV4) in adults 18–64 years old. Model inputs included 2018–2020 vaccine effectiveness (VE) estimates based on medical record data from a large local health system, 2019–2020 national vaccination and influenza epidemic parameters, with costs and population distributions fitted to the season. ResultsAmong adults ages 18–64 years, RIV4 cost $94,186/QALY gained, compared to SD-IIV4. Among those 50–64 years old, RIV4 was relatively more cost-effective ($61,329/QALY gained). Cost-effectiveness estimates for 18–64-year-olds were sensitive to the absolute difference in VE between SD-IIV4 and RIV4, among other parameters. Use of RIV4 in 18–64-year-olds would result in fewer cases (669,984), outpatient visits (261,293), hospitalizations (20,046) and deaths (1,018) annually. The majority (59 %; 597 of 1018) of the decreases in deaths occurred in the 50–64-year-olds. ConclusionsWhile RIV4 was effective and cost-effective relative to SD-IIV4 for both 50–64-year-old and 18–64-year-old adults, cost-effectiveness was sensitive to small changes in parameters among 18–64-year-olds. Because substantial public health benefits occur with enhanced vaccines, health systems and policy makers may opt for preferential product use in select age/risk groups (e.g., 50–64 year olds) to maximize their cost-benefit ratios.