Effective parenteral vaccines are available to control rabies in dogs. While such vaccines are successfully used worldwide, the period between vaccine boosters required to guarantee protection of the population against rabies varies between vaccines and populations. In Flores Island, Indonesia, internationally and locally produced rabies vaccines are used during annual vaccination campaigns of predominantly free-roaming owned domestic dogs. The study objective was to identify the duration of the presence and factors associated with the loss of adequate level of binding antibodies (≥0.5 EU/ml) following rabies vaccination in a domestic dog population on Flores Island. A total of 171 dogs that developed an antibody titre higher or equal to 0.5 EU/ml 30 days after vaccination (D30), were repeatedly sampled at day 90, 180, 270, and 360 after vaccination. On the day of vaccination (D0), an interview was performed with dog owners to collect information on dog characteristics (age, sex, body condition score (BCS)), history of rabies vaccination, kind of daily food, frequency of feeding, and origin of the dog. Serum samples were collected and the level of antibodies was quantitatively assessed using ELISA tests. Dogs were categorized as having an adequate level of binding antibodies (≥0.5 EU/ml) or inadequate level of binding antibodies (<0.5 EU/ml) at each time points examined. A total of 115, 72, 23, and 31 dogs were sampled at D90, D180, D270, and D360, respectively, with the highest proportion of antibodies ≥ 0.5 EU/ml (58%, 95% CI, 49-67%) at D90, which reduced gradually until D360 (35%, 95% CI, 19-52%). Multivariable logistic regression models showed that loss of adequate level of binding antibodies is significantly associated with dogs having no history of vaccination or vaccination applied more than 12 months before D0, being less than 12 months of age, and having a poor BCS. These results highlight the importance of BCS regarding the immune response duration and provide insights into frequency of vaccination campaigns required for the internationally available vaccine used on Flores Island. For dogs without vaccination history or vaccination being applied more than 12 months before D0, a booster is recommended within 3 months (a largest drop of antibodies was detected within the first 90 days) after the first vaccination to guarantee measurable protection of the population that lasts at least for one year.

中文翻译：

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印度尼西亚弗洛勒斯岛，接种疫苗的狗群中狂犬病结合抗体的丧失。


有效的肠外疫苗可用于控制狗的狂犬病。虽然此类疫苗已在世界范围内成功使用，但保证人群免受狂犬病侵害所需的疫苗加强接种间隔时间因疫苗和人群而异。在印度尼西亚弗洛勒斯岛，每年的疫苗接种活动中都会使用国际和当地生产的狂犬病疫苗，主要对象是自由漫游的家养狗。该研究的目的是确定弗洛勒斯岛家犬群在接种狂犬病疫苗后存在的持续时间以及与足够水平的结合抗体（≥0.5 EU/ml）丧失相关的因素。总共 171 只狗在疫苗接种后 30 天（D30）产生的抗体滴度高于或等于 0.5 EU/ml，在疫苗接种后第 90、180、270 和 360 天重复取样。在疫苗接种当天（D0），与狗主人进行访谈，收集狗的特征（年龄、性别、身体状况评分（BCS））、狂犬病疫苗接种史、日常食物种类、喂食频率等信息。狗的起源。收集血清样本并使用 ELISA 测试定量评估抗体水平。在每个检查时间点，狗被分类为具有足够水平的结合抗体（≥0.5 EU/ml）或结合抗体水平不足（<0.5 EU/ml）。分别在 D90、D180、D270 和 D360 时对总共 115、72、23 和 31 只狗进行了采样，抗体≥ 0.5 EU/ml 的比例最高（58%、95% CI、49-67%） D90 时逐渐降低，直至 D360（35%，95% CI，19-52%）。 多变量逻辑回归模型显示，缺乏足够水平的结合抗体与没有疫苗接种史或在 D0 之前 12 个月以上接种疫苗、年龄小于 12 个月以及 BCS 较差的狗显着相关。这些结果强调了 BCS 在免疫反应持续时间方面的重要性，并提供了对弗洛勒斯岛使用的国际疫苗所需的疫苗接种活动频率的见解。对于没有疫苗接种史或在 D0 之前超过 12 个月接种过疫苗的犬只，建议在第一次疫苗接种后 3 个月内（​​在前 90 天内检测到抗体的最大下降）进行加强免疫，以确保对群体持续提供可衡量的保护至少一年。