Protection against multiply drug-resistant and geographically distant strains of Haemonchus contortus by vaccination with H11, a gut membrane-derived protective antigen.
H11 is a "hidden antigen" derived from adult Haemonchus contortus which is capable of conferring a high degree of protection against subsequent challenge. To be commercially useful, any vaccine based on this antigen must protect against field strains and drug-resistant worms. The results show that vaccination with H11 affords high levels of protection against the multiply drug-resistant (MDR) Lawes strain of Haemonchus contortus. Moreover, there was no difference in protection whether the H11 was extracted from drug-resistant or susceptible worms, indicating that multiple drug-resistance does not significantly alter the immunogenicity of H11. Ideally, a commercial vaccine based on this antigen should also be capable of protecting against strains from geographically separate areas, so that it is not necessary to manufacture "region-specific" vaccines. Vaccination with H11 purified from either Australian or U.K. Haemonchus contortus was effective in protecting against subsequent challenge with Australian larvae, indicating that one type of H11 should have world-wide application.
Newton
S E
SE
Pitman-Moore Australia Ltd, Research Unit, North Melbourne, Victoria, Australia.
Morrish
L E
LE
Martin
P J
PJ
Montague
P E
PE
Rolph
T P
TP
D000818:Animals; D000909:Antibodies, Helminth / Q000097:blood; D000947:Antigens, Helminth / Q000276:immunology*; D001315:Australia; D018826:CD13 Antigens; D004306:Dose-Response Relationship, Immunologic; D004351:Drug Resistance / Q000276:immunology; D006188:Haemonchiasis / Q000276:immunology / Q000517:prevention & control*; D006189:Haemonchus / Q000145:classification / Q000276:immunology* / Q000302:isolation & purification; D015801:Helminth Proteins / Q000276:immunology*; D006400:Hematocrit; D008565:Membrane Proteins / Q000276:immunology*; D010270:Parasite Egg Count; D012756:Sheep; D006113:United Kingdom; D014611:Vaccination; D014612:Vaccines / Q000276:immunology
D000909:Antibodies, Helminth; D000947:Antigens, Helminth; D015801:Helminth Proteins; D008565:Membrane Proteins; D014612:Vaccines; D018826:CD13 Antigens; C080908:H11 protein, Haemonchus contortus