Tetanus toxoids (TT) commercially available for use in horses and livestock are commonly used to vaccinate elephants and rhinoceros that are in human care. Although recommendations for booster intervals have changed in human and horse protocols to reduce the risks associated with hyper-immunity (i.e. B-cell anergy and hypersensitivity reactions) these have generally not been adopted in zoo protocols. Additionally, there is no evidence to demonstrate commercial TT immunogenicity in rhinoceros. In this study, a preliminary analysis of rhinoceros antibody responses to TT was conducted, in addition to an exploration of the impact of various booster frequencies on antibody responses in elephant. Retrospective analysis of archived serum samples was conducted for 9 Asian elephants (Elephas maximus), 7 southern black (Diceros bicornis minor), one southern white (Ceratotherium simum simum), and two greater one-horned (Rhinoceros unicornis) rhinoceros. Pre-vaccination (baseline) samples and those following priming vaccination (rhinoceros only), annual and non-annual boosters were targeted. A commercially available competitive ELISA kit was used to quantify serum anti-TT antibodies. Average baseline and post-vaccination anti-tetanus antibody concentrations were greater in elephant (92 mg/L ± 42, n = 3, N = 3; 125 ± 76, n = 82, N = 9) than in rhinoceros (47 mg/L ± 39, n = 8, N = 8; 44 mg/L ± 37, n = 16, N = 7). Rhinoceros antibody concentrations did not differ markedly following vaccinations from their naturally acquired high pre-vaccination concentrations. Eight elephants demonstrated antibody maintenance for 3–5 years without a tetanus booster. Additionally, although five out of nine elephants developed local reactions consistent with delayed type IV hypersensitivity following some boosters, there was no association between high antibody concentrations and increased incidence of adverse reactions. In addition, no decrease in antibody concentrations was detected as a result of annual vaccination in elephants, though this does not entirely rule out potential for B-cell anergy.

可用于马和牲畜的市售破伤风类毒素 (TT) 通常用于为人类照料的大象和犀牛接种疫苗。尽管人类和马方案中对加强间隔的建议已经改变，以降低与超免疫相关的风险（即 B 细胞无能和超敏反应），但动物园方案中通常没有采用这些方案。此外，没有证据表明犀牛中的商业 TT 免疫原性。在这项研究中，除了探索各种加强频率对大象抗体反应的影响外，还对犀牛对 TT 的抗体反应进行了初步分析。对 9 头亚洲象(Elephas maximus)、7 头南方黑象的存档血清样本进行回顾性分析(Diceros bicornis minor)、一只南方白(Ceratotherium simum simum)和两只大独角犀牛 (Rhinoceros unicornis)犀牛。疫苗接种前（基线）样本和初次疫苗接种后（仅限犀牛）、年度和非年度加强剂的样本是目标。市售的竞争性 ELISA 试剂盒用于量化血清抗 TT 抗体。大象的平均基线和接种后抗破伤风抗体浓度（92 mg/L ± 42，n = 3，N = 3；125 ± 76，n = 82，N = 9）高于犀牛（47 mg/L L ± 39，n = 8，N = 8；44 mg/L ± 37，n = 16，N = 7)。接种疫苗后犀牛抗体浓度与其自然获得的接种前高浓度没有显着差异。八头大象在没有破伤风增强剂的情况下表现出 3-5 年的抗体维持。此外，尽管九头大象中有五头在一些增强剂后出现了与迟发性 IV 型超敏反应一致的局部反应，但高抗体浓度与不良反应发生率增加之间没有关联。此外，大象每年接种疫苗并未检测到抗体浓度降低，但这并不能完全排除 B 细胞无反应性的可能性。