Local immunity in the pig respiratory tract. I. -- Cellular and humoral immune responses following swine influenza infection.

By serial lung washings on living pigs, kinetics of humoral and cellular local immune responses have been studied following intranasal inoculation of swine influenza virus. Local and serum antibodies appeared 8 days post-infection (p.i.) and reached a maximal titer 2 weeks p.i. Antibody titer decreased faster in lung secretions than in serum. Local and systemic cell-mediated immune responses were detected, by in vitro transformation tests, during the second week p.i.