Inoculation of pigs against Trichinella spiralis, using larval excretory-secretory antigens.

Pigs were inoculated with Trichinella spiralis excretory-secretory products derived from short-term in vitro maintenance of infective muscle larvae. Intraperitoneal administration of excretory-secretory products in Freund's complete adjuvant or aluminum hydroxide induced moderate, but variable, degrees of immunity to challenge exposure in a nondose-dependent manner; IM administration of products in Freund's incomplete adjuvant was less successful. Inoculated pigs harbored fewer adult worms, and the fecundity of female worms (numbers of newborn larvae shed in vitro) recovered after challenge exposure was significantly lower (alpha = 0.05) than the fecundity of females recovered from control pigs. The degree of resistance in inoculated pigs was directly related to serotiter against excretory-secretory antigens, as determined in an enzyme-linked immunosorbent assay.