Neuraminidase inhibitors are a class of antivirals that have activity against both influenza A and B viruses. Influenza neuraminidase cleaves terminal sialic acid residues and damages the receptors recognized by viral hemagglutinin, thereby facilitating release of virus from infected cells. In the presence of a neuraminidase inhibitor, release of virus from infected cells is impaired and the progeny viruses that are freed clump together, as sialic acid has not been cleaved.
The FDA has approved the first nasally administered flu vaccine. This cold-adapted, temperature sensitive, attenuated, trivalent vaccine is manufactured by MedImmune Vaccine, Inc. and marketed by MedImmune and Wyeth under the name FluMist. The nasal flu vaccine should be available this fall.