Wera Ewaldus, Warembourg Charlotte, Bulu Petrus M, Siko Maria M, Dürr Salome
Animal Health Study Program, Kupang State Agricultural Polytechnic (Politeknik Pertanian Negeri Kupang), Kupang, Indonesia.
Vetsuisse Faculty, Veterinary Public Health Institute, University of Bern, Bern, Switzerland.
Front Vet Sci. 2022 Jun 9;9:868380. doi: 10.3389/fvets.2022.868380. eCollection 2022.
Vaccination is the main tool to prevent the circulation of rabies in dog populations. The development of an immune response after vaccination differs between individual dogs and depends on many factors such as dog characteristics, management, or genetics. Here, we first investigated the level of, and associated factors for, the presence of binding antibodies in 130 healthy dogs from Flores Island, Indonesia. Secondly, we identified factors associated with the development of binding antibodies within 30 days after vaccination among a subsample of dogs that had a binding antibody titre <0.5 EU/ml at the day of vaccination (D0, = 91). Blood samples were collected from the individual dogs immediately before vaccination at D0 and 30 days after vaccination (D30). The rabies antibody titres were determined using ELISAs. Information on potential risk factors such as the dog's age and sex, history of vaccination, type and frequency of feeding, and BCS (body condition score) were gathered during interviews at D0. Regression analyses were performed to identify the risk factors associated with the presence of binding antibody titre ≥0.5 EU/ml at D0 for the 130 dogs and the development of binding antibody titre ≥0.5EU/ml at D30 for the 91 dogs. The results showed that the proportion of dogs with antibody titre ≥0.5 EU/ml was 30% (39/130) at D0. The only factors found to be significantly influencing the presence of binding antibodies titres ≥0.5 EU/ml was previous vaccination within 1 year before D0 [46.8 vs. 14.7%, Odds ratio (OR) = 3.6, 95%CI 1.5-9.3; -value = 0.006], although the same trend was found for dogs of higher age and better BCS. Eighty-six percent (79/91) of dogs whose rabies binding antibody level was <0.5 EU/ml at D0 had developed an adequate immune response (≥0.5 EU/ml) at D30. Almost a significantly higher proportion developed an adequate immune response in dogs of good BCS compared to those of poor BCS (95.3% vs. 79.2%, OR = 4.7, 95%CI 1.1-32.5; -value = 0.057. Twelve (13.2%) dogs retain binding antibody level <0.5 EU/ml at D30, indicating poor immune response after vaccination. A majority of them did not receive vaccine before D0 according to the owner and had poor BCS (83.3%; 10/12). Our findings show the high effectiveness of rabies vaccine in under field conditions to develop measurable immunity and the importance of a good BCS, often achievable by good dog keeping conditions, for developing efficient immunity after parenteral vaccination in dogs.
疫苗接种是预防狂犬病在犬类群体中传播的主要手段。接种疫苗后免疫反应的发展在个体犬之间存在差异，并且取决于许多因素，如犬的特征、管理方式或基因。在此，我们首先调查了印度尼西亚弗洛雷斯岛130只健康犬体内结合抗体的水平及相关因素。其次，在接种日（D0）结合抗体滴度<0.5 EU/ml的犬的子样本中，我们确定了接种后30天内结合抗体产生的相关因素（n = 91）。在D0接种前和接种后30天（D30）立即从个体犬采集血样。使用酶联免疫吸附测定法（ELISA）测定狂犬病抗体滴度。在D0访谈期间收集有关潜在风险因素的信息，如犬的年龄和性别、疫苗接种史、喂养类型和频率以及体况评分（BCS）。进行回归分析以确定与130只犬在D0时结合抗体滴度≥0.5 EU/ml的存在以及91只犬在D30时结合抗体滴度≥0.5 EU/ml的产生相关的风险因素。结果显示，在D0时抗体滴度≥0.5 EU/ml的犬的比例为30%（39/130）。发现唯一显著影响结合抗体滴度≥0.5 EU/ml存在的因素是在D0前1年内曾接种过疫苗[46.8%对14.7%，优势比（OR）= 3.6，95%置信区间1.5 - 9.3；P值 = 0.006]，尽管在年龄较大和体况评分较好的犬中也发现了相同趋势。在D0时狂犬病结合抗体水平<0.5 EU/ml的犬中，86%（79/91）在D30时产生了足够的免疫反应（≥0.5 EU/ml）。与体况评分差的犬相比，体况评分好的犬产生足够免疫反应的比例几乎显著更高（95.3%对79.2%，OR = 4.7，95%置信区间1.1 - 32.5；P值 = 0.057）。12只（13.2%）犬在D30时结合抗体水平仍<0.5 EU/ml，表明接种疫苗后免疫反应不佳。根据主人的说法，其中大多数在D0前未接种疫苗且体况评分差（83.3%；10/12）。我们的研究结果表明，狂犬病疫苗在野外条件下产生可测量免疫力的有效性很高，以及良好的体况评分对于犬经皮下接种疫苗后产生有效免疫力的重要性，良好的体况评分通常可通过良好的养犬条件实现。
