Cost-Effectiveness Analysis of Maternal Respiratory Syncytial Virus Vaccine in Protecting Infants from RSV Infection in Japan

Abstract

Introduction: Respiratory syncytial virus (RSV) is one of the major causes of respiratory tract infections among children. Until recently, the monoclonal antibody palivizumab was the only RSV prophylaxis available in Japan. In 2024, the bivalent RSV prefusion F protein-based (RSVpreF) vaccine was approved for the prevention of RSV infection in infants by active immunization of pregnant women. In this study, we assessed the cost-effectiveness of a combined strategy of RSVpreF vaccine and palivizumab in Japanese setting.

Methods: Using a Markov model, we evaluated prevented cases and deaths of medically attended RSV infections from birth to age 11 months for each of the three healthcare settings: inpatient (hospitalization), emergency department visits, and outpatient visits. Incremental cost-effectiveness ratios (ICERs) were calculated from economic outcomes (intervention costs, medication costs, and productivity losses) and quality-adjusted life years (QALYs). Further, we calculated the maximum price of RSVpreF vaccine within which the program would be cost-effective.

Results: In comparison with the current prophylaxis (palivizumab alone), a combined prophylaxis of year-round RSVpreF vaccination of pregnant women and palivizumab prescription for premature infants born in < 32 weeks gestational age (wGA) and all infants with high risk prevented 14,382 medically attended cases of RSV (hospitalization, 7490 cases; emergency department, 2239 cases; outpatient, 4653 cases) and 7 deaths, respectively. From a healthcare payer perspective, when the price of RSVpreF vaccine was equal to or less than ¥23,948 (US $182), a combination prophylaxis was cost-effective under the ICER threshold of ¥5 million per QALY. The other combination prophylaxis of year-round RSVpreF vaccination and palivizumab prescription of premature born in < 32 wGA regardless of risk in infants was a dominant strategy (more effective and less costly).

Conclusion: A combined prophylaxis of year-round RSVpreF vaccine and palivizumab could be a cost-effective strategy to protect neonates throughout the infant stage (< 1 years old) in Japan.

Keywords: Cost-effectiveness analysis; Japan; Palivizumab; RSVpreF; Respiratory syncytial virus; Vaccination.

Fig. 1

Decision tree structure for cost-effectiveness analysis. In the cost-effectiveness analysis, a new combination RSV prophylaxis was compared with the current prophylaxis by epidemiology, costs, and cost-effectiveness. Neonates were divided into subgroups by their mothers’ vaccination status and subsequent usage of prophylaxis. RSV incidence, usage of medical resources, and subsequent mortality and productivity losses were calculated for each of the subgroups. RSV respiratory syncytial virus

Fig. 2

Incremental cost-effectiveness ratio with various RSVpreF vaccine price. Dynamics of ICERs for two combination prophylaxis strategies (blue, scenario 1; orange, scenario 2) upon changing the RSVpreF vaccine price were explored from a (A) payer perspective and (B) societal perspective. Exchange rate was US $1 = ¥131.4. ICER incremental cost-effectiveness ratio, RSV respiratory syncytial virus, RSVpreF vaccine RSV prefusion F protein-based vaccine, QALY quality-adjusted life year

Fig. 3

One-way deterministic sensitivity analysis for scenario 1 from a societal perspective. Tornado diagram for the outcomes of DSA. Upon changing the value ranges of the parameter, ± 25% of each parameter was used as upper (red) and lower (blue) bounds. Input parameters are listed on the left. The analysis was conducted from a societal perspective in Japanese yen (US $1 = ¥131.4). RSVpreF vaccine price was ¥23,948 (US $182). DSA deterministic sensitivity analysis, ED emergency department, ICER incremental cost-effectiveness ratio, OC outpatient, RSV respiratory syncytial virus, RSVH RSV hospitalization, QALY quality-adjusted life year