OBJECTIVES: The aim of this study is to estimate the potential cost-effectiveness (CE) of using a maternal vaccine or long-acting monoclonal antibody in the Argentine context

METHODS: We used a static cohort model with a finely disaggregated age structure to calculate the costs and consequences of using RSVpreF and Nirsevimab over a 10-year period (2025-2034), assuming both year-round and seasonal administration. We compared each intervention to no RSV intervention and to each other. The primary outcome was the discounted cost per disability-adjusted life year (DALY) averted from a societal perspective. We used recent Argentine RSV costing and disease surveillance data together with efficacy data from clinical trials. We ran probabilistic and deterministic uncertainty analyses.

RESULTS: Both products could prevent at least 25% of RSV deaths aged <5 years. With a price-per-dose of $US50, both products have a high probability of being CE compared to no intervention (US$5,285 [95%CI US$3,794-US$9,891] and US$5,335 [95%CI US$3,793-US$9,914] per DALY averted for year-round use of Nirsevimab and RSVpreF, respectively) assuming a willingness-to-pay threshold set at 90% the GDP/capita. Similar health impact could be achieved by using a 6-month seasonal strategy, and this could improve CE by around 40%.

CONCLUSIONS: Both RSVpreF and Nirsevimab could be worth consideration in Argentina if priced at ≤US$ 50 per dose. Cost-effectiveness is highly dependent on the dose price and could be improved with the implementation of a seasonal immunization strategy.