RESUMO
Crude antigen preparations from different life-cycle stages of T. spiralis using 10 mug and 100 mug antigen/dose were tested for their ability to immunize mice against homologous challenge infection. Immunization was assessed by accelerated expulsion of adult worms, reduction in female worm fecundity and decreased yield of muscle larvae. The dose of 100 mug proved to be more protective in all antigen preparations. The AA provided highly significant protection against adult stages [89%] and muscle larvae [80%]. NLA produced highly significant protection against muscle larvae only [76%]. MLA provided highly significant protection against adult stages [74%], female fecundity [74%] and muscle larvae [80%]. Combination of AA and MLA produced highly significant protection against adult stages [96%], female fecundity [73%] and muscle larvae [86%]. The results showed that all antigen preparations provided variable, considerable, but partial protection against challenge infection. The variations in immunization potential were discussed