Arnoux Sandie, Bidan Fabrice, Damman Alix, Petit Etienne, Assié Sébastien, Ezanno Pauline
INRAE, Oniris, BIOEPAR, 44300 Nantes, France.
Institut de L'élevage, 42 rue Georges Morel, F-49070 Beaucouzé, France.
Vaccines (Basel). 2021 Oct 6;9(10):1137. doi: 10.3390/vaccines9101137.
Bovine viral diarrhoea (BVD) remains an issue despite control programs implemented worldwide. Virus introduction can occur through contacts with neighbouring herds. Vaccination can locally protect exposed herds. However, virus spread depends on herd characteristics, which may impair vaccination efficiency. Using a within-herd epidemiological model, we compared three French cow-calf farming systems named by their main breed: Charolaise, Limousine, and Blonde d'Aquitaine. We assessed vaccination strategies of breeding females assuming two possible protections: against infection or against vertical transmission. Four commercial vaccines were considered: Bovilis, Bovela, Rispoval, and Mucosiffa. We tested various virus introduction frequency in a naïve herd. We calculated BVD economic impact and vaccination reward. In Charolaise, BVD economic impact was 113€ per cow over 5 years after virus introduction. Irrespective of the vaccine and for a high enough risk of introduction, the yearly expected reward was 0.80€ per invested euro per cow. Vaccination should not be stopped before herd exposure has been decreased. In contrast, the reward was almost nil in Blonde d'Aquitaine and Limousine. This highlights the importance of accounting for herd specificities to assess BVD impact and vaccination efficiency. To guide farmers' vaccination decisions against BVD, we transformed this model into a French decision support tool.
尽管全球都实施了防控计划，但牛病毒性腹泻（BVD）仍然是个问题。病毒可通过与邻近牛群接触而传入。疫苗接种可在局部保护受感染牛群。然而，病毒传播取决于牛群特征，这可能会削弱疫苗接种效果。我们使用一个牛群内流行病学模型，比较了法国三种以主要品种命名的奶牛 - 犊牛养殖系统：夏洛来牛、利木赞牛和阿基坦黄白花牛。我们假设两种可能的保护措施：预防感染或预防垂直传播，评估了繁殖母牛的疫苗接种策略。考虑了四种商业疫苗：博维利斯（Bovilis）、博维拉（Bovela）、瑞思波瓦尔（Rispoval）和穆科西法（Mucosiffa）。我们在一个未感染的牛群中测试了各种病毒传入频率。我们计算了BVD的经济影响和疫苗接种回报。在夏洛来牛养殖系统中，病毒传入后5年内，每头牛的BVD经济影响为113欧元。无论使用哪种疫苗，对于足够高的传入风险，每头牛每年的预期回报为每投入1欧元获得0.80欧元。在牛群暴露减少之前，不应停止疫苗接种。相比之下，在阿基坦黄白花牛和利木赞牛养殖系统中，回报几乎为零。这凸显了考虑牛群特异性以评估BVD影响和疫苗接种效果的重要性。为指导养殖户针对BVD的疫苗接种决策，我们将该模型转化为一个法语决策支持工具。
