Animal Health Study Program, Kupang State Agricultural Polytechnic (Politeknik Pertanian Negeri Kupang), Kupang, Indonesia.
Veterinary Public Health Institute, Vetsuisse Faculty, University of Bern, Bern, Switzerland.
PLoS Negl Trop Dis. 2021 Sep 7;15(9):e0009688. doi: 10.1371/journal.pntd.0009688. eCollection 2021 Sep.
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.
有效的狂犬病疫苗可用于控制犬类狂犬病。虽然这些疫苗在世界范围内得到成功应用，但为确保人群免受狂犬病的侵害，不同疫苗和人群之间所需的疫苗加强针接种间隔时间有所不同。在印度尼西亚弗洛雷斯岛上，国际和当地生产的狂犬病疫苗在主要为自由放养的家养犬的年度疫苗接种活动中使用。本研究的目的是确定在弗洛雷斯岛上的家养犬群体中，接种狂犬病疫苗后，结合抗体（≥0.5 EU/ml）水平持续存在的时间以及与结合抗体（≥0.5 EU/ml）水平降低相关的因素。共有 171 只犬在接种疫苗后 30 天（D30）时抗体滴度高于或等于 0.5 EU/ml，在接种后 90 天、180 天、270 天和 360 天分别进行重复采样。在接种疫苗的当天（D0），对犬主人进行访谈，收集犬的特征（年龄、性别、体况评分（BCS））、狂犬病疫苗接种史、日常食物种类、喂养频率和犬的来源等信息。采集血清样本，采用 ELISA 试验定量评估抗体水平。在每个检查时间点，将犬分为具有足够结合抗体（≥0.5 EU/ml）水平的组和结合抗体（<0.5 EU/ml）水平不足的组。在 D90、D180、D270 和 D360 分别有 115、72、23 和 31 只犬被采样，D90 时具有足够结合抗体（≥0.5 EU/ml）的犬的比例最高（58%，95%CI，49-67%），该比例逐渐降低，直至 D360 时（35%，95%CI，19-52%）。多变量逻辑回归模型显示，结合抗体水平丧失与犬无疫苗接种史或在 D0 前 12 个月以上接种疫苗、年龄小于 12 个月和体况评分较差显著相关。这些结果强调了体况评分对免疫反应持续时间的重要性，并为弗洛雷斯岛使用的国际可用疫苗所需的疫苗接种频率提供了见解。对于无疫苗接种史或在 D0 前 12 个月以上接种疫苗的犬，建议在第一次接种后 3 个月（检测到抗体最大降幅发生在最初的 90 天内）内进行加强免疫，以确保对人群的可测量保护持续至少一年。
