1. A protein found on the surface of influenza viruses and other pathogens that binds to red blood cells and enables the virus to attach to and infect host cells.
Usage: technical; medical; virology

Examples

• Hemagglutinin is one of the two main surface proteins of the influenza virus.
• The flu vaccine targets the hemagglutinin protein to help the immune system recognize the virus.
• Scientists study hemagglutinin mutations to predict which flu strains will circulate each season.
• Antibodies against hemagglutinin can prevent the virus from entering cells.
• The H in H1N1 refers to the type of hemagglutinin present on that influenza strain.