Antigen distortion allows influenza virus to escape neutralization

The structure of the hemagglutinin (HA) of a mutant influenza virus that escapes neutralization by a nonclonal antibody shows that the mutation causes changes in HA structure which avoid and energetically less favorable conformation, However, the structure of the mutant HA-center-dot-Fab complex indicates that the antibody binds selectively to mutant HA in a wild type-like distorted conformation. The association of an antibody with a less favored HA conformation represents an alternative to previousness described mechanisms of escapes from neutralization by antibodies.