title: Vaccination in murine schistosomiasis with adult worm-derived antigens: variables influencing protection in outbred mice.
abstract: Previous studies have shown that both permissive (mouse) and partially permissive (rabbit) hosts develop high levels of resistance against Schistosoma mansoni infection after vaccination with a multiple antigen extract (SE) obtained by incubation of living adult worms in saline, plus bacterial adjuvant. To investigate variables influencing SE-induced protection in murine schistosomiasis, a series of distinct vaccination protocols were performed focussing on the immunization dose, carrier systems, route, site and amplitude of challenge infection, and time between immunization and challenge. In addition, a new approach was adopted to evaluate SE protective activity, by means of population analysis of worm burden frequency distributions in a large scale study of vaccination in outbred Swiss mice. Distinct curves of frequency and a drastic difference in worm burden distribution of frequencies from SE-vaccinated x non-vaccinated mice were found. It was shown that SE could generate 75% mean protection in outbred mice even in the absence of adjuvant. In addition SE immunization was also able to induce full protection against lethal infection. SE-induced protection could be modulated by such parameters as dose of SE immunization/challenge interval, and route of cercariae injection. These data show that SE yields very high protective activity in outbred mice, and may provide a further insight for rational design of a vaccine in experimental schistosomiasis.
authors.affiliation: Department of Helminthology, Institute Oswaldo Cruz, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil.
authors.forename: M
authors.initials: M
authors.lastname: Tendler
authors.forename: R M
authors.initials: RM
authors.lastname: Pinto
authors.forename: A de O
authors.initials: Ade O
authors.lastname: Lima
authors.forename: W
authors.initials: W
authors.lastname: Savino
authors.forename: N
authors.initials: N
authors.lastname: Katz
mesh_terms: D000818:Animals; D000947:Antigens, Helminth / Q000276:immunology*; D004306:Dose-Response Relationship, Immunologic; D005620:Freund's Adjuvant; D007117:Immunization, Secondary; D008297:Male; D051379:Mice; D012550:Schistosoma mansoni / Q000276:immunology*; D012555:Schistosomiasis mansoni / Q000517:prevention & control*; D014611:Vaccination
chemical_list: D000947:Antigens, Helminth; D005620:Freund's Adjuvant