Human Respiratory Syncytial Virus (HRV) is a member of the genus Orthopneumovirus, mainly divided into two subtypes: A and B. HRV is an enveloped single-stranded negative-sense RNA virus, with a structure that includes glycoproteins G and F, fusion protein F, phosphoprotein P, and nucleoprotein N, among other. HRV primarily infects respiratory epithelial cells, causing cell fusion to form syncytia and leading to respiratory diseases such as bronchiolitis and pneumonia. HRV infection activates the host cell's immune response, including inflammatory responses and antiviral immune responses. The genome of HRV exhibits high variability, leading to diversity in viral strains and complexity in epidemiological characteristics. Mutations in HRV may affect the virus's transmissibility and pathogenicity, as well as the host's immune response.