Haemonchus contortus is the most important gastrointestinal nematode in the tropics and subtropics causing huge economic losses to the small ruminant industry. Vaccination is potentially a sustainable approach to control this parasite and the performance of Barbervax® a vaccine containing integral membrane glycoproteins from H. contortus intestinal cells, was evaluated in naturally infected grazing sheep during their development from sucking lambs to adults. The sheep were randomly assigned to two groups: Vaccine and Control. The Vaccine group were vaccinated 23 times over the course of this two-year trial at intervals of 3–6 weeks. They responded with anti-vaccine specific antibodies, had 80 % lower Haemonchus egg counts and were less anaemic compared with the controls. Packed cell volumes (PCV) were always greater than 25 % in the vaccinated sheep but averaged between 23 % and 24 % in the controls. Total plasma protein values were higher in the vaccinated group from the third vaccination until the end of the trial. Throughout the trial, 88 % of the control sheep were drenched (average of 3.1 drenches per treated animal) but only 57 % of vaccinates, needed a salvage anthelmintic treatment (average of 1.9 drenches per treated animal), however, between group no differences in body weight were observed. In summary, these results indicate that a continuous course of Barbervax® can provide lambs with substantial year-round protection against H. contortus until they reached adulthood.

捻转血矛线虫是热带和亚热带地区最重要的胃肠道线虫，给小型反刍动物业造成巨大的经济损失。疫苗接种可能是控制这种寄生虫的可持续方法，Barbervax®（一种含有来自扭伤扭伤肠细胞的完整膜糖蛋白的疫苗）的性能在自然感染的放牧羊从吸吮羔羊到成年的发育过程中进行了评估。这些羊被随机分配到两组：疫苗组和对照组。在为期两年的试验过程中，疫苗组接种了 23 次疫苗，接种间隔为 3-6 周。与对照组相比，他们产生了抗疫苗特异性抗体，血矛线虫卵数量减少了 80%，贫血程度也减轻了。接种疫苗的绵羊的细胞堆积体积 (PCV) 始终大于 25%，但对照组的平均值在 23% 到 24% 之间。从第三次疫苗接种到试验结束，接种组的血浆总蛋白值较高。在整个试验过程中，88% 的对照羊被淋湿（平均每只接受治疗的动物 3.1 次淋湿），但只有 57% 的接种者需要挽救性驱虫药治疗（每只接受治疗的动物平均 1.9 次淋湿），然而，各组之间在观察体重。总之，这些结果表明，Barbervax® 的连续疗程可以为羔羊提供全年有效的针对H. contortus 的保护，直到它们成年。