Genomic monitoring of RSV in patients and wastewater samples in Tyrol – a pilot project

Respiratory Syncytial Virus (RSV) is a major cause of illness and hospitalization among children, particularly in infants under one year of age. The monoclonal antibody Nirsevimab that targets the FØ site of pre-fusion F protein, was approved in 2022 to protect infants during their first RSV season. Austria introduced the immunization in the routine vaccination program in December 2024. While highly effective, its widespread use may create selective pressure for resistant viral variants.

In this study, we aim to perform genomic characterization of respiratory syncytial virus (RSV) circulating during the 2025/26 RSV season using a modern next generation sequencing method. Our particular focus will be on identifying viral variants  that may potentially be associated with reduced susceptibility to Nirsevimab. Any detected mutations in the F protein will be further evaluated using phenotypic inhibition assays in a cell culture setup.

In an effort to track circulating “variants” at a community level, we also intend to genetically characterize RSV obtained from wastewater samples collected at 42 sites.

The study will be conducted in collaboration with the pediatric departments of the University Hospital, as well as the district hospitals in Kufstein and St. Johann. For the wastewater project, we are collaborating with the Institute of Legal Medicine (GMI) at the Medical University of Innsbruck.

The project is financially supported by the Tyrolean Science Fund (TWF).