Implications of morphological variation in influenza viruses

SUMMARY Pleomorphism in influenza viruses, characterized by diverse morphological forms ranging from spherical virions to elongated filaments, has been suggested to present significant implications for pathogenesis. This review examines the role of pleomorphism on the influenza virus life cycle, encompassing viral attachment and entry, replication, assembly, and budding, as well as transmission dynamics. It explores the determinants' underlying morphological variability in virions and their impact on viral fitness and host interactions. Insights into how pleomorphic forms of the virus influence disease severity and the efficacy of antivirals are discussed. Understanding the implications of pleomorphism in influenza virus pathogenesis is crucial for the development of effective disease prevention, control, and treatment strategies.