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An Improved and High Throughput Respiratory Syncytial Virus (RSV) Micro-neutralization Assay
Published on: January 26, 2019
Detection of nirsevimab-resistant RSV-B variants in children carrying the F:N201T substitution through genomic
María Iglesias-Caballero1, Jose A Infantes1, Albert Campoy1
1Laboratory of Reference and Research in Respiratory Viruses, National Centre for Microbiology, Instituto de Salud Carlos III, Majadahonda, Spain.
Abstract:
During Spain's 2025/26 RSV season, three children were infected with RSV-B viruses carrying the F protein N201T substitution. Two who received nirsevimab that season were hospitalised (one required intensive care); the third was treated previously. Recombinant expression studies confirmed reduced nirsevimab recognition. Genomic data indicated sporadic emergence across distinct RSV-B backgrounds rather than expansion of a single lineage. Findings highlight the importance of combining genomic surveillance with antigenic characterisation to detect and interpret variants with reduced susceptibility to antibody-based prevention.
