Scientists at Vanderbilt have discovered a new class of human antibodies specific to a novel target for the detection, prevention, and treatment of influenza A viruses (IAV). Using structural characterization, they have identified a novel antigenic site on the hemagglutin (HA) head domain that may be targeted by multiple antibodies simultaneously in a non-competitive manner. They found that administration of these antibodies against an otherwise lethal challenge with viruses of H1N1, H3N2, H5N1, or H7N9 subtypes confers protection when used as prophylaxis or therapy against major IAV subtypes that are pathogenic to humans. These antibodies may prove effective as a universal influenza treatment or in the design of a universal influenza vaccine.