Cell mediated immune response of chicks following fowl adenovirus type-1 infection.

Cellular immune response of 6-week-old chickens infected with fowl adenovirus type-1 was evaluated by both in vivo and in vitro assay. In vitro assay, enumerating peripheral T lymphocyte by alphanaphthyl acetate esterase staining, revealed that cellular immunity appeared as early as 1 week post-infection and was maintained up to 5 weeks post-infection. In vivo assay by phytohaemagglutin skin test showed cellular immunity until 2 weeks post-infection. Thereafter no immunity was observed by this assay.