title: Protective immunity to the blood-feeding nematode Haemonchus contortus induced by vaccination with parasite low molecular weight antigens.
abstract: Partially purified low molecular weight antigens obtained by gel filtration of whole worm homogenates or total adult excretory-secretory (ES) products were tested in a vaccination experiment to determine their ability to induce protective immunity against Haemonchus contortus in sheep. Sheep were challenged with 20,000 infective 3rd-stage larvae. One animal in the low molecular weight vaccinated group showed no protection against H. contortus, whereas the 4 other sheep in this group showed a mean reduction of 99.9% in faecal egg counts and of 97.6% in abomasal worm burden compared to the non-vaccinated controls and the adjuvant controls. The ES-vaccinated sheep showed a 32.2% reduction in parasite egg production and a 63.7% reduction in abomasal worm counts. Analysis of the humoral immune responses revealed no significant differences in antibody recognition of putative protective antigens between the protected and non-protected vaccinated animals. However, a marked lower lymphocyte proliferation response was found in non-protected sheep.
authors.affiliation: Utrecht University, Department of Parasitology and Tropical Veterinary Medicine, The Netherlands. H.Schallig@vetmic.dgk.ruu.nl
authors.forename: H D
authors.initials: HD
authors.lastname: Schallig
authors.forename: M A
authors.initials: MA
authors.lastname: Van Leeuwen
mesh_terms: D000818:Animals; D000909:Antibodies, Helminth / Q000097:blood; D000947:Antigens, Helminth / Q000276:immunology*; D006188:Haemonchiasis / Q000276:immunology / Q000469:parasitology / Q000517:prevention & control / Q000662:veterinary*; D006189:Haemonchus / Q000276:immunology* / Q000502:physiology; D008213:Lymphocyte Activation; D008970:Molecular Weight; D010270:Parasite Egg Count / Q000662:veterinary; D012756:Sheep; D012757:Sheep Diseases / Q000276:immunology* / Q000469:parasitology / Q000517:prevention & control; D014611:Vaccination / Q000662:veterinary; D014612:Vaccines / Q000276:immunology*
chemical_list: D000909:Antibodies, Helminth; D000947:Antigens, Helminth; D014612:Vaccines