Abstract
Clesrovimab, an extended half-life monoclonal antibody, aims to protect infants for an entire RSV season. The pandemic impacted RSV epidemiology and strategies were implemented to support clesrovimab trials. Near real-time monitoring of data showed minimal RSV activity in 2020. In 2021, RSV resurged early in some countries and was delayed in others, resulting in a change in trial enrollment strategy.