I — Influenza Virus
Influenza viruses are segmented, negative-sense RNA viruses in the Orthomyxoviridae family. Influenza viruses infect respiratory epithelial cells, causing direct cytopathic effects and triggering innate immune activation. Severe disease is associated with exaggerated inflammatory responses, diffuse alveolar damage, and secondary bacterial pneumonia.
Clinically, influenza presents with fever, myalgia, cough, and malaise; high-risk populations may develop viral pneumonia and ARDS. Research focuses on universal vaccine development targeting conserved epitopes (e.g., HA stem), antiviral resistance mechanisms, and host determinants of severe disease.
Their genome comprises eight RNA segments encoding proteins including hemagglutinin (HA), neuraminidase (NA), and polymerase subunits (PB1, PB2, PA). Replication occurs in the nucleus, where the viral polymerase “cap-snatches” host mRNA caps to prime transcription.
Antigenic drift results from accumulation of point mutations in HA and NA, while antigenic shift occurs through reassortment of genome segments between different strains, enabling pandemics. Avian reservoirs play a key role in viral evolution.
Influenza viruses are segmented, negative-sense RNA viruses in the Orthomyxoviridae family. Influenza viruses infect respiratory epithelial cells, causing direct cytopathic effects and triggering innate immune activation. Severe disease is associated with exaggerated inflammatory responses, diffuse alveolar damage, and secondary bacterial pneumonia.
Clinically, influenza presents with fever, myalgia, cough, and malaise; high-risk populations may develop viral pneumonia and ARDS. Research focuses on universal vaccine development targeting conserved epitopes (e.g., HA stem), antiviral resistance mechanisms, and host determinants of severe disease.
Their genome comprises eight RNA segments encoding proteins including hemagglutinin (HA), neuraminidase (NA), and polymerase subunits (PB1, PB2, PA). Replication occurs in the nucleus, where the viral polymerase “cap-snatches” host mRNA caps to prime transcription.
Antigenic drift results from accumulation of point mutations in HA and NA, while antigenic shift occurs through reassortment of genome segments between different strains, enabling pandemics. Avian reservoirs play a key role in viral evolution.