Novel Antibodies Against Annual or Pandemic Influenza Viruses

Influenza virus surface antigens mutate frequently, which forces manufacture of new vaccines of varying efficacy each year. Scientists have searched in vain for a conserved, unchanging epitope that could be used as a target for neutralizing antibodies.

A multi-institutional U.S. team reported that it has identified neutralizing antibodies that attach to a pocket at the base of the hemagglutinin molecule and thereby prevent the virus from entering cells. These neutralizing antibodies were effective against many strains of influenza A virus, including the current lethal H5N1 “bird flu” strain and the lethal H1N1 strain that caused the pandemic of 1918–1919. In mice, these antibodies lowered infection both in vitro and in vivo. Furthermore, the…