Human antibody reveals hidden vulnerability in influenza virus

The ever-changing ‘head’ of an influenza virus protein has an unexpected Achilles heel, report scientists. The team discovered the structure of a naturally occurring human antibody that recognizes and disrupts a portion of the hemagglutinin (HA) protein that the virus uses to enter and infect cells. The investigators determined that the antibody, FluA-20, binds tightly to an area on the head of the HA protein that is only briefly accessible to antibody attack.