H and N are two distinct proteins found on the surface of the influenza virus. H stands for hemagglutinin and N stands for neuraminidase. They have very exact shapes that can bind, like a key in its lock, with places on the surface of cells in the respiratory tract. There are 16 different H proteins and 9 different N proteins, which means there are 144 possible HN combinations. The subtypes of type A influenza viruses are named according to these H and N protein combinations. For example, H5N1 refers to a subtype with hemagglutinin (H) type 5 and neuraminidase (N) type 1. The particular strain of avian influenza virus that has infected poultry, some wild birds and a number of people in other parts of the world is the highly pathogenic subtype H5N1.
These resources are brought to you by the Cooperative Extension System and your Local Institution
Welcome
eXtension is an interactive learning environment delivering the best, most researched knowledge from the smartest land-grant university minds across America.
eXtension: more mind reach
Have a question? Try asking one of our Experts
Have a specific question? Try asking one of our Experts
Unlike most other resources on the web, we have experts from Universities around the country ready to answer your questions.