Future Prophylaxis Strategies in RSV: End of the Status Quo

OBJECTIVES: Respiratory syncytial virus (RSV) is a seasonal respiratory virus and a leading cause of lower respiratory tract infections in infants and elderly. Current preventive strategies are limited to palivizumab, but new prophylactic treatments such as monoclonal antibodies (mAbs) and vaccines are expected to be launched soon. We conducted a landscape analysis to anticipate what would be the different future prevention strategies for RSV.

METHODS: Desk research and literature reviews were conducted in April 2022, looking at multiple sources such as PubMed, Citeline and Datamonitor. Outcomes of interest were (for mAbs/vaccines): target population(s), estimated price and coverage per target population and expected barriers.

RESULTS: Next generation mAbs nirsevimab is being developed in infants and will be available for the 2023/24 season. Two immunization strategies can be extrapolated: universal immunization or targeted immunization focusing on at-risk individuals. The choice of the strategy will significantly be impacted by drug price and recommendation from national bodies. As such, nirsevimab price could range between $500 - $3,000/dose depending on the strategy, with a coverage of 20-50% during the first year of commercialization. Vaccines will be available in 2024/25 and are being explored in three target populations: pregnant women, pediatric and elderly populations. Maternal immunization aims at protecting newborns via transplacental antibody transfer and protection is estimated to last up to 6 months. Coverage is estimated between 20-75% during the first year of launch at a price of $30-$40/dose. Similar coverage is expected in elderly, with a vaccine price between $30-$150/dose in case of annual vaccination or $200-$300/dose if only one injection is required.

CONCLUSIONS: Future RSV vaccines and mAbs will address a significant unmet need which remained unattended for long. However, important uncertainties remain around the future prevention strategies for RSV and particularly how nirsevimab use will evolve once vaccines will be available.