# Genetic Diversity in the Fusion Gene of Respiratory Syncytial Virus (RSV) Isolated From Iraqi Patients: A First Report

## TL;DR

This study reports genetic diversity in the fusion gene of RSV from Iraqi patients and suggests it could impact vaccine development and antiviral strategies.

## Contribution

The study provides the first molecular evaluation of RSV's fusion gene in Iraqi patients and identifies potential implications for vaccine and antiviral development.

## Key findings

- Nucleotide changes in the RSV fusion gene were identified and grouped into clades related to isolates from Austria, Argentina, Finland, and France.
- In silico modeling of amino acid changes in the fusion gene produced good-predicted models for antiviral screening.
- Genetic diversity in the fusion gene may influence vaccine development as it is a primary antigen target for RSV.

## Abstract

Molecular evaluation of the respiratory syncytial virus (RSV) genome is one of the common strategies applied to understand the viral pathogenicity and control its spreading. In this study, we carried out molecular evaluation on the targeted fusion (F) gene region in the RSV-positive samples of Iraqi patients during the autumn and winter of 2022/2023. One hundred and fifty patients with lower respiratory tract infections were screened for RSV using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Sanger sequencing was performed on the RSV-positive samples targeting 1061 nucleotides (from nucleotide 6168 to 7228 within the RSV genome) and 1000 nucleotides (from nucleotide 6122 to 7121 within the RSV genome) of the F gene region for RSV-A and RSV-B, respectively. The results showed some nucleotide changes within the targeted F gene, which were grouped in distinct clade, closely related to isolates from Austria, Argentine, Finland, and France through phylogenetic analysis. In silico protein modeling using the SWISS-MODEL and I-TASSER web tools based on nonsynonymous changes of amino acid sequence showed some good-predicted models that can be utilized for antiviral screening. In summary, the identified nucleotide variations in the F gene could influence vaccine development as the F protein is the primary target for the major antigen of RSV. Molecular surveillance data of RSV local isolates are also essential for studying new genomic changes and enable the prediction of potential new antiviral agents.