Hemagglutination Inhibition (HI) Assay of Influenza Viruses with Monoclonal Antibodies

Heamagglutination is inhibited when antibodies are present because antibodies to the influenza virus will prevent attachment of the virus to red blood cells. The highest dilution of antibody that prevents hemagglutination is called the HI titer. Human monoclonal antibodies generated from single human B cells were tested to characterize their ability to inhibit hemagglutination against virus A/California/07/2009 (H1N1) and A/Brisbane/10/2007 (H3N2).