A goal in fighting influenza is a universal vaccine, one that works on many strains of the pathogen [see “Beating the Flu in a Single Shot”; Scientific American, June 2008]. But the virus’s outer coat, consisting mainly of proteins called hemagglutinin and neuraminidase, frequently mutate, forcing the reformulation of vaccines every season. Two studies report the discovery of human antibodies that target an area on hemagglutinin that does not change much. (In contrast, current drugs, such as Tamiflu, aim for neuraminidase.) In tests, one of the antibodies protected mice from lethal doses of avian flu (H5N1) and other strains. Large amounts were needed, however, so any human treatment could be expensive. The papers were published in the March Nature Structural and Molecular Biology and online February 26 by Science Express.