VIRUS ANIMATIONS: FLU VIRUS
VIRUS: Influenza Virus Particles
Animation of influenza virus particles. Flu viruses are covered by spikes of Haemagglutinin (slender knob-like projections-trimers) and Neuraminidase (the 4-part squarish-looking projections), hence the H and N names, such as H5N1 or H1N1. Flu viruses have a segmented genome which can get jumbled up during replication (causing gene mixing or reassortment). Consequently, different strains easily form from existing types. Flu occurs in seasonal epidemics and periodically as major pandemics. Often preventable by vaccination. Because flu is so variable, new vaccines have to be formulted each year to combat the latest variants.