Cost-effectiveness of nirsevimab and maternal RSVpreF for preventing respiratory syncytial virus disease in infants across Canada.

Background: Nirsevimab, a long-acting monoclonal antibody, and RSVpreF, a maternal vaccine, are newly approved respiratory syncytial virus (RSV) prophylactics for infants in Canada. Both have the potential to expand prevention efforts, but there is limited evidence regarding their cost-effectiveness and how it varies across the country, despite disparate hospitalisation rates and resource use among different populations.

Methods: We developed a decision tree model to follow twelve monthly birth cohorts through their first year of life, incorporating risk differentiation based on Canadian region, prematurity, and comorbidities.