Evaluation of the potential impact and cost-effectiveness of respiratory syncytial virus (RSV) prevention strategies for infants in Argentina

Background. New interventions are available for the prevention of respiratory syncytial virus (RSV) disease in young infants. We aimed to assess the potential impact and cost-effectiveness of using a long-acting monoclonal antibody (RSV mAb) or maternal RSV vaccine in the Argentine context. Methods. We used a static proportionate outcomes model to calculate the costs and consequences of using RSV mAb or maternal RSV vaccine over a ten-year period (2025-2034) in Argentina, assuming both year-round and seasonal administration. We compared each intervention to no pharmaceutical RSV intervention. The primary outcome was the discounted cost per disability-adjusted life year (DALY) averted from a societal perspective. We assumed willingness-to-pay of US$ 12,285 per DALY averted (0.9 times the national gross domestic product per capita). We used population study data on costs and disease burden and the efficacy of clinical trials of both interventions as inputs. We ran deterministic and probabilistic uncertainty analyses. Findings. Either strategy (RSV mAb or maternal RSV vaccine) could prevent >25% of RSV deaths aged <5 years and similar to 30% aged <6 months (the age group where most intervention impact occurs). With a dose price of $US 50, both products have a 100% probability of being cost-effective compared to no intervention (US$ 5283 [95%CI $5203-$5363] and US$ 5522 [95%CI $5427 - $5617] per DALY averted for year-round use of RSV mAb and maternal RSV vaccine, respectively). Similar health impact could be achieved by a six-month seasonal strategy, which could improve cost-effectiveness by around 45% (assuming the dose price is unchanged). Interpretation. Either RSV mAb or maternal RSV vaccine are worth consideration in Argentina when priced at <= US$ 50 per dose. A seasonal strategy could improve cost-effectiveness.