Evaluating the Benefits of RSV Maternal Vaccination Using a Scottish National Dataset

This study will use a retrospective cohort design and will be conducted within routinely collected national healthcare and statutory demographic datasets held by PHS and National Records of Scotland (NRS). As such, there will be no active enrollment of study participants, no direct contact with study participants, no collection of any primary data outside of the standard of care (SOC), and no requirement for informed consent. This study design was chosen due to several advantages, over other possible designs, including the ability to evaluate incidence of study outcomes in exposed and unexposed infants, ability to follow infants longitudinally to evaluate study outcomes through 12 months of age, and ability to evaluate all-cause outcomes. Study endpoints, including RSV-associated LRTD hospitalization and RSV-associated hospitalization, among infants born to ABRYSVO-vaccinated mothers (exposed group) will be compared with those among infants born to ABRYSVO-unvaccinated mothers (comparison group) initially from birth through 6 months of age, with later analysis from birth through 12 months as the infants reach this age threshold and their data become available.

Infants must meet all inclusion criteria to be eligible for inclusion in the study: 1. Live birth in Scotland from 1st September 2024 to 28th February 2026 2. Gestational age at birth ≥28(0/7) weeks of gestation (earliest gestational age eligible for ABRYSVO vaccination) Infants meeting any of the following criteria will not be included in the study: 1. Born to a mother who received any licensed or investigational RSV vaccine other than ABRYSVO at any time during pregnancy 2. Meets UK national guidelines for monoclonal antibody receipt