Flu's Tricky Tricks

摘要

After vaccination against influenza A virus, single-point mutations are selected in hemagglutinin (the virus molecule that binds to sialic acid molecules on the surface of host cells) that escape neutralization by polyclonal antibody responses. Hensley et al. (p. 734) have discovered that in mice these mutations increased the virus's avidity for sialic acid. Amino acid substitutions that occur during reiterations of immune escape and avidity modulation can thus drive antigenic variation.