Ascaris suum--vaccination of mice with liposome encapsulated antigen.

Vaccination with liposome encapsulated adult crude antigen with and without coencapsulated immunomodulator (levamisole) in a mice/larval Ascaris suum model provided protection against a challenge infection (2000 eggs) in mice immunised by immobilised antigen. The best results (88.9% protection) were obtained with a combination of two doses of liposome entrapped antigen with leamisole. Vaccination with liposome vaccine without modulator was slightly less effective (78.7% protection). A single dose of vaccine was ineffective (14.3% protection). Application of the soluble antigen without any adjuvants led to the enhancement of worm yield in lungs and liver.