Khatri N, Nichani A K, Sharma R D, Khatri M, Malhotra D V
Department of Veterinary Medicine, CCS Haryana Agricultural University, Hisar, India.
Vet Res Commun. 2001 Apr;25(3):179-88. doi: 10.1023/a:1006473307868.
The responses were monitored of young crossbred calves vaccinated against tropical theileriosis during the winter against a field tick challenge in the disease season. Thirty-eight calves below 2 months of age, born after the end of the disease season, were selected at an organized farm. Twenty-five animals were vaccinated with Theileria annulata (Hisar) cell culture vaccine (developed at CCS HAU Hisar laboratory) after the end of the disease season and 13 calves were kept as non-vaccinated controls. These calves were observed for their susceptibility to theileriosis in the new disease season. There was an increase in antibody titre in 18 of the 25 vaccinated animals one month after vaccination. The antibody titre then declined gradually, but remained higher than those of the non-vaccinated animals at month 0. No fever or other clinical signs of tropical theileriosis were observed in any of the vaccinated animals. Nine out of 25 (36%) vaccinated calves showed occasional piroplasms (<0.5%) in blood smears. All the vaccinated animals withstood the field tick challenge. On the other hand, 9 of the 13 (69%) unvaccinated calves exhibited occasional piroplasms, and included three clinical cases of tropical theileriosis. These observations suggest that young crossbred calves vaccinated with the T. annulata (Hisar) cell culture vaccine at the end of the disease season were relatively resistant during the next disease season.
对冬季接种热带泰勒虫病疫苗的杂交幼犊在疾病季节进行田间蜱虫攻击试验时的反应进行了监测。在一个有组织的农场中，挑选了38头在疾病季节结束后出生的2月龄以下的犊牛。25头动物在疾病季节结束后接种了环形泰勒虫（希萨尔株）细胞培养疫苗（由CCS HAU希萨尔实验室研制），13头犊牛作为未接种疫苗的对照。观察这些犊牛在新的疾病季节对泰勒虫病的易感性。25头接种疫苗的动物中有18头在接种后1个月抗体滴度升高。抗体滴度随后逐渐下降，但在第0个月时仍高于未接种疫苗的动物。在任何接种疫苗的动物中均未观察到发热或热带泰勒虫病的其他临床症状。25头接种疫苗的犊牛中有9头（36%）在血涂片中偶尔出现梨形虫（<0.5%）。所有接种疫苗的动物都经受住了田间蜱虫的攻击。另一方面，13头未接种疫苗的犊牛中有9头（69%）偶尔出现梨形虫，其中包括3例热带泰勒虫病临床病例。这些观察结果表明，在疾病季节结束时接种环形泰勒虫（希萨尔株）细胞培养疫苗的杂交幼犊在下一个疾病季节相对具有抵抗力。
