Abstract: | Attempts were made to immunise rats and mice against infection with F. hepatica by oral dosing with T. hydatigena eggs, or by vaccination with various T. hydatigena antigen preparations. These antigens included extracts from T. hydatigena cysticerci and cyst fluid, and antigens collected during short-term (48 h) and long-term (14 days) in vitro cultivation of larvae. Immunity was assessed by the numbers of F. hepatica recovered from the challenge infection in rats, and the mortality rates of infected mice. None of the immunisation regimes with T. hydatigena antigens induced consistent, significant immunity. This was in contrast to the high level of immunity shown by rats dosed orally with F. hepatica metacercariae four weeks prior to challenge infection. |