The attenuated influenza-A-virus strain "Alice" (H3N2) - A Recombination from A2/England/72 and A/PR8 Mount Sinai/34 - was given intransally in drops (10(7,2) ID50 per dose), twice seven days apart. In a similar fashion, 25 healthy persons received placebos. Local antibodies were determined before and three weeks after the first vaccination from nasal irrigation fluid. The fluid was concentrated and adjusted to an IgA amount of 50 mg/l. Blood samples were obtained at similar intervals. Systemic antibody formation was comparable to that obtained with inactivated virus vaccine. There was good antibody formation against retrospective and prospective virus strains of the actual drift period. The conversion rate of antineuraminidase antibodies was comparable to that obtained with inactivated virus vaccine. The locally induced antibodies behaved predominantly in a strain-specific manner. However, there were also reactions with the virus strains Port Chalmers and Hong Kong. Live vaccine should in future be used in "drift" times, while inactivated virus vaccine should be used in shift periods (occurrence of new virus strains).