Comparative Cost-Effectiveness Analysis of Respiratory Syncytial Virus Vaccines for Older Adults in Hong Kong.

Two respiratory syncytial virus (RSV) vaccines (AREXVY ® and ABRYSVO ® ) were recently approved for older adults in the US. This study aimed to evaluate the cost-effectiveness of AREXVY ® and ABRYSVO ® from the Hong Kong public healthcare provider's perspective. A two-year decision-analytical model was developed to examine the outcomes of a single RSV vaccination (AREXVY ® or ABRYSVO ® ) compared to no vaccination. Primary outcomes included RSV-related health outcomes, direct medical costs, quality-adjusted life-year (QALY) loss, and incremental cost per QALY (ICER). RSV vaccines are not yet marketed in Hong Kong, base-case analysis, therefore, benchmarked US RSV vaccine prices at 4 levels (25%, 50%, 75%, 100%). AREXVY ® and ABRYSVO ® (versus no vaccination) gained 0.000568 QALY and 0.000647 QALY, respectively. ICERs of ABRYSVO ® (26,209 USD/QALY) and AREXVY ® (47,485 USD/QALY) were lower than the willingness-to-pay threshold (49,594 USD/QALY) at 25% US vaccine price. The RSV attack rate was a common influential factor at all vaccine price levels. The probabilities of AREXVY ® and ABRYSVO ® to be most cost-effective were 0.10% and 97.68%, respectively, at 25% US vaccine price. Single vaccination of ABRYSVO ® or AREXVY ® for older adults appears to gain QALYs over 2 years in Hong Kong. The cost-effectiveness of AREXVY ® and ABRYSVO ® is subject to vaccine price and RSV attack rate.