Budget Impact of Strategies Involving RSVpreF and Nirsevimab to Protect Infants in Saudi Arabia Against Respiratory Syncytial Virus

INTRODUCTION: Respiratory syncytial virus (RSV) manifesting as lower respiratory tract illness (LRTI; RSV-LRTI) has a significant clinical and economic impact for infants in the Kingdom of Saudi Arabia (KSA) and globally. We evaluated the budget impact (BI) of strategies involving maternal vaccine (RSVpreF) and single-dose monoclonal antibody (nirsevimab) to protect KSA infants against RSV-LRTI. METHODS: A deterministic cohort model evaluated the clinical and economic burden of RSV-LRTI and the impact of interventions among five annual birth cohorts of infants aged < 1 year. Parameter values were estimated on the basis of published sources using KSA-specific data to the extent possible. Model outcomes included RSV-LRTI episodes (hospital, emergency department [ED], primary care [PC]), disease-attributable deaths, medical care costs, and intervention costs (in US$). Nirsevimab alone (herein "Nirs"; price: $1005.78; uptake: 90%) and, alternatively, mixed approach RSVpreF (price: $217.07; uptake: 14.3%) with nirsevimab (uptake: 90%) for unprotected infants ("MV + Nirs") were compared against no intervention ("NoInt"). RESULTS: NoInt would yield 2,115,924 cases (hospital: 85,898, ED: 943,770, PC: 1,086,255) and $817.9 million in medical care costs. Nirs would prevent 1,206,819 cases and $470.1 million in medical care costs; with $2054.3 million in intervention costs, BI would be $1.6 billion. Compared with NoInt, MV + Nirs would prevent 1,143,754 cases and $457.1 million in medical care costs; with $1851.6 million in intervention costs (MV: $78.6, Nirs: $1773.0), BI would be $1.4 billion. CONCLUSIONS: Findings suggest that either strategy would substantially reduce the burden of RSV-LRTI. Even with low uptake, adding RSVpreF (mixed approach) yielded considerably lower budget impact compared with nirsevimab alone.