To evaluate the efficacy over 1 year against culture-confirmed influenza-illness caused by community-acquired subtypes antigenically similar to those contained in the vaccine, in adults aged ≥ 60 years at enrollment, of 1 dose of an intranasally-administered (IN) liquid formulation of influenza virus vaccine, trivalent, types A and B, live, cold-adapted (CAIV-T; Wyeth, Marietta, PA, USA) compared with saline placebo.