Attenuated live trivalent vaccine update

Aviron began a total of three Phase I or I/II trials with two versions of an attenuated live trivalent influenza vaccine. A Phase I/II trial in 240 healthy adults will use an older version of the vaccine. A Phase I/II trial in 240 healthy children and a Phase I trial in 20 healthy adults will use a version containing newer strains.

The vaccine, which is administered intranasally, is designed to disperse to the mucosal lining of the upper airway to give a protective immune response. Aviron said it deletes or modifies virulence proteins or creates mutations in the genetic machinery of viral replication to strike a balance between infectivity and immunogenicity. ...