Detection and tissue localization of components of the immune complex in animals infected and immunized with influenza virus.

Mice previously vaccinated or convalescents after infection with mouse-adapted influenza virus were challenged by various routes with live or inactivated virus. The components of the immune complex (antigen-antibody-complement) could be detected by immunofluorescence in lungs, kidneys, and heart. The frequency of positive immunofluorescence reaction was related to serum antibody level and, to some extent, to the route the animals were challenged.