A vaccine containing doses ranging from 2 μg to 50 μg of integral membrane proteins from Haemonchus contortus intestinal cells (H11 and H-gal-GP complex) has been shown to be effective for lambs. A vaccine for H. contortus was tested in two-month old grazing Corriedale lambs during an eight-month trial on the outskirts of Bagé, Rio Grande do Sul, Brazil. The animals were kept in a single paddock and allocated to five similar groups according to weight, sex and faecal egg counts (FEC). Vaccinated lambs received 0, 2, 5, 10 or 50 μg of the same antigen diluted in QuilA adjuvant. Vaccine injections were given at days 0, 21, 49, 91, 133, and 175. Lambs were sampled weekly for FEC, packed cell volume (PCV), and plasma ELISA antibody titre. Lambs with PCVs ≤15 % were drenched with levamisole (7.5 mg/kg body weight) as a salvage treatment. During days 77–98 an artificial challenge was administered to increase parasite transmission. Post-artificial challenge (from day 98–217), the FEC of the vaccinated lambs were 59.3 % lower than those of the control lambs. Antigen dose correlated with changes in PCV (r = 0.387 p-value < 0.001). Vaccinated lambs also had higher PCV than controls (p < 0.001; contrast analysis). Salvage treatment was needed in 16.7 % of vaccinated lambs and 88 % of control lambs.

一种含有 2 μg 至 50 μg 来自扭曲血球虫肠道细胞（H11 和 H-gal-GP 复合物）的整合膜蛋白的疫苗已被证明对羔羊有效。H. contortus疫苗在巴西南里奥格兰德州巴热郊区进行的为期八个月的试验中，对两个月大的放牧 Corriedale 羔羊进行了测试。这些动物被饲养在一个围场中，并根据体重、性别和粪便卵数 (FEC) 分为五个相似的组。接种疫苗的羔羊接受在 QuilA 佐剂中稀释的 0、2、5、10 或 50 μg 相同抗原。在第 0、21、49、91、133 和 175 天进行疫苗注射。每周对羔羊进行采样以检测 FEC、细胞压积 (PCV) 和血浆 ELISA 抗体滴度。PCV ≤ 15 % 的羔羊用左旋咪唑（7.5 毫克/千克体重）浸湿作为补救治疗。在第 77-98 天期间，进行了人工攻击以增加寄生虫传播。人工攻击后（从第 98 天到第 217 天），接种羔羊的 FEC 比对照羔羊的 FEC 低 59.3%。抗原剂量与 PCV 的变化相关（r = 0.387 p 值 < 0.001）。接种疫苗的羔羊的 PCV 也高于对照组（p < 0.001；对比分析）。16.7% 的接种羔羊和 88% 的对照羔羊需要挽救治疗。