2.And type A's can be divided into further sub-categories, depending on the subtypes of two proteins present on their surface: hemagglutinin, 'H', and neuraminidase, 'N'.
3.Antibodies for the flu are primarily directed against the two proteins on the surface of the influenza virus, hemagglutinin (H) and neuraminidase (N).
4.Sold under the names Tamiflu and Rolenza, these drugs have been said to work by blocking the protein neuraminidase that viruses use to escape their host cells.