Optimal Respiratory Syncytial Virus intervention programmes using Nirsevimab in England and Wales

Abstract

Introduction Respiratory Syncytial Virus (RSV) is a major cause of acute lower respiratory tract infections (ALRI) in infants. There are no licensed vaccines and only one monoclonal antibody available to protect infants from disease. A new and potentially longer-lasting monoclonal antibody, Nirsevimab, showed promising results in phase IIb/III trials. We evaluate the cost-effectiveness of Nirsevimab intervention programmes in England and Wales Methods We used a dynamic model for RSV transmission, calibrated to data from England and Wales. We considered a suite of potential Nirsevimab programmes, including administration to all neonates (year-round); only neonates born during the RSV season (seasonal); or neonates born during the RSV season plus infants less than six months old before the start of the RSV season (seasonal + catch-up). Results If administered seasonally to all infants at birth, we found that Nirsevimab would have to be priced less than 63 GPB per dose for at least 50% certainty that it could cost-effectively replace the current Palivizumab programme, using an ICER threshold of 20,000 GPB/QALY. An extended seasonal programme which includes a pre-season catch-up becomes the optimal strategy below a 34 GPB/dose purchasing price for at least 50% certainty. At a purchasing price per dose of 5-32 GPB, the annual implementation costs of a seasonal programme could be as high as 2 million GPB before a switch to a year-round strategy would be optimal. Discussion Nirsevimab has the potential to be cost-effective in England and Wales not only for use in high-risk infants.