Description: Publication date: 25 July 2018 Source: Vaccine, Volume 36, Issue 31 Author(s): Nienke M. Scheltema, Xynthia M. Kavelaars, Kentigern Thorburn, Marije P. Hennus, Job B. van Woensel, Cornelis K. van der Ent, José A.M. Borghans, Louis J. Bont, Julia Drylewicz Background Respiratory syncytial virus (RSV) infection is an important cause of infant mortality. Here, we estimated the potential impact of maternal vaccination against RSV on life-threatening RSV infection in infants. Methods We developed a mathematical model for maternal vaccine-induced antibody dynamics and used characteristics of a maternal RSV vaccine currently in phase 3 of clinical development. The model was applied to data from two cohorts of children younger than 12 months with RSV-related paediatric intensive care unit (PICU) admission in the United Kingdom (n = 370) and the Netherlands (n = 167), and a cohort of 211 children younger than 12 months with RSV-related in-hospital death from 20 countries worldwide. Results Our model predicted that, depending on vaccine efficiency, maternal vaccination at 30 weeks’ gestational age could have prevented 62–75% of RSV-related PICU admissions in the United Kingdom and 76–87% in the Netherlands. For the global mortality cohort, the model predicted that maternal vaccination could have prevented 29–48% of RSV-related in-hospital deaths. Preterm children and children with comorbidities were predicted to benefit less than (healthy) term children. Conclusions Maternal vaccination against RSV may substantially decrease life-threatening RSV infections in infants.