Cost-effectiveness Analysis of Maternal Immunization with RSVpreF Vaccine for the Prevention of Respiratory Syncytial Virus Among Infants in Spain.

Introduction: Respiratory syncytial virus (RSV) is the leading cause of acute lower respiratory infections (ALRI) in children under one year of age. In high-income countries, RSV infections cause a significant overload of care every winter, imposing a significant burden to the healthcare system, which has made the development of prevention strategies a major global health priority. In this context, a new bivalent RSV prefusion F protein-based vaccine (RSVpreF) has recently been approved. The objective of this study was to evaluate the cost-effectiveness of vaccinating pregnant women with the RSVpreF vaccine to prevent RSV in infants from the Spanish National Healthcare System (NHS) perspective.

Methods: A hypothetical cohort framework and a Markov-type process were used to estimate clinical outcomes, costs, quality-adjusted life years (QALY) and cost-per-QALY gained (willingness-to-pay threshold: €25,000/QALY) for newborn infants born to RSV-vaccinated versus unvaccinated mothers over an RSV season. The base case analysis was performed from the NHS perspective including direct costs (€2023) and applying a discount of 3% to future costs and outcomes. To evaluate the robustness of the model, several scenarios, and deterministic and probabilistic analyses were carried out. All the parameters and assumptions were validated by a panel of experts.

Results: The results of the study showed that year-round maternal vaccination program with 70% coverage is a dominant option compared to no intervention, resulting in direct cost savings of €1.8 million each year, with an increase of 551 QALYs. Maternal vaccination could prevent 38% of hospital admissions, 23% of emergency room visits, 19% of primary care visits, and 34% of deaths due to RSV. All scenario analyses showed consistent results, and according to the probabilistic sensitivity analysis (PSA), the probability of maternal vaccination being cost-effective versus no intervention was 99%.

Conclusions: From the Spanish NHS perspective, maternal vaccination with bivalent RSVpreF is a dominant alternative compared with a non-prevention strategy.