Influenza ۲۰۲۵ Review: Antigenic Trends, Vaccine Impact, and Public Health Challenges

Background: The ۲۰۲۵ influenza season is characterized by antigenic stability in major seasonal strains and the emergence of novel avian influenza variants. This review synthesizes current evidence on the epidemiology, virology, vaccine effectiveness, and public health challenges for both seasonal and avian influenza in ۲۰۲۵.Materials and Methods: A narrative review was conducted using literature from PubMed, Scopus, Web of Science, WHO, CDC, and Google Scholar up to March ۲۰۲۵. Included studies were original research, systematic reviews, surveillance reports, and official guidelines on circulating strains, vaccine effectiveness, emerging variants, and interventions. Two reviewers independently screened and selected studies, extracting data on virus subtypes, vaccine composition, surveillance updates, and public health measures.Results: A/H۱N۱pdm۰۹ and B-Victoria lineages remained antigenically stable, supporting continued vaccine effectiveness, while A/H۳N۲ continued to drift, necessitating annual vaccine updates. The B/Yamagata lineage was undetected, prompting a transition to trivalent vaccines for ۲۰۲۵–۲۰۲۶. Emerging avian influenza variants, notably H۱۰N۳ and H۵N۱, highlighted ongoing zoonotic risks, but sustained human-to-human transmission was not observed. For the ۲۰۲۴–۲۰۲۵ season, vaccine effectiveness ranged from ۳۶–۵۴% in adults and reduced pediatric hospitalizations by ۶۳–۷۸%. Enhanced surveillance, including real-time genetic tracking and multidisciplinary analyses, improved outbreak detection, but challenges persisted in vaccine strain selection, production timelines, and equitable distribution.Conclusion: The ۲۰۲۵ influenza season demonstrates the challenge of maintaining vaccine effectiveness amid stable strains and emerging avian variants. Vigilant surveillance, adaptive vaccine strategies, and coordinated public health responses remain essential. The shift to trivalent vaccines and adoption of advanced surveillance tools emphasize the ongoing need for innovation and equity in influenza control.

کلیدواژه ها:

Challenges ، Emerging variants ، Influenza ۲۰۲۵ ، seasonal influenza