Host-parasite relationships of Fasciola hepatica in the white mouse. VII. effects of anti-worm incubate sera on transferred worms and successful vaccination with a crude incubate antigen.

Mouse antisera against the 16-day-old worm incubate and sera from 25-day infections in mice debilitated migrating flukes in recipient animals as measured by worm recovery and host mortality. Mouse antisomatic and 100-day infection sera produced no such effects. Host mortality was significantly lower after challenge in mice given one ip immunizing injection of the worm incubate; however, worm recovery was not significantly reduced. Injections at 2, 7, 12, and 24 hr with the worm incubate elaborated over a 24-hr period protected 75% of the mice from infection after challenge, and reduced the worm burden by 83.3%.