Whole-Genome Sequencing of RSV and Phylogeographic Assessment of Viral Importations into Russia.

Lower respiratory tract infections caused by the respiratory syncytial virus (RSV) pose a major global public health challenge. The use of next-generation sequencing technologies enables detailed monitoring of viral genetic variability, which is crucial for evaluating the efficacy of immunoprophylactic measures. In this study, whole-genome sequencing of RSV was performed on 106 samples collected in the Russian Federation between September 2021 and April 2025. Three NGS platforms were employed: Illumina MiSeq, Oxford Nanopore Technologies MinION, and Qitan Tech QNome-3841. Using discrete phylogeographic methods, we estimated a minimum of 45 introduction events into Russia for RSV-A and 39 for RSV-B among the genomes included in the analysis. Most events were represented by a single Russian genome. These results indicate recurrent introductions of RSV into Russia from abroad. Given the limited genomic sampling available, most of these introductions were not associated with detectable transmission within the country.