NA

Neuraminidase (NA) is another major glycoprotein on the surface of influenza viruses. The primary function of influenza NA is cleaving of the sialic acid receptors to facilitate the release of viral particles from infected cells. In contrast to HA antibodies, NA antibodies are not known to inhibit the viral infectivity, but they have been shown to reduce viral yield by inhibiting NA enzymatic activity, thus also contributing to protection against influenza infection.