Department of Veterinary Infectious Diseases and Avian Diseases, College of Veterinary Medicine and Center for Poultry Diseases Control, Chonbuk National University, South Korea.
Department of Veterinary Infectious Diseases and Avian Diseases, College of Veterinary Medicine and Center for Poultry Diseases Control, Chonbuk National University, South Korea.
Vet Microbiol. 2018 Jun;219:107-112. doi: 10.1016/j.vetmic.2018.04.021. Epub 2018 Apr 14.
Duck viral hepatitis type I is a rapidly spreading infection lethal in young ducklings, caused by the duck hepatitis A virus (DHAV). Vaccination of breeder ducks is a common practice to control DHAV. However, maintaining proper maternal antibody levels in large flocks is difficult. Therefore, a simple vaccination strategy that can induces stable high antibody levels through mass vaccination is desirable. We evaluated a DHAV vaccination strategy for breeder ducks involving oral administration under field conditions, and examined the kinetics of antibody response in the ducks and their progeny. The strategy included a primary intramuscular vaccination, followed by secondary and tertiary oral vaccinations. Five weeks after the primary vaccination, virus-neutralizing antibody titers increased by 8.4 ± 1.3 log. The titers remained stable at around 9.0 ± 1.1 log for up to 36 weeks. None of the progeny died when challenged with virulent DHAV at 1, 7 or 14 days of age. The transfer percentage of antibodies from the breeder ducks to their progeny was 12.8 ± 3.0%. When antibody levels of the progeny were measured from the day of hatching to 20 days of age, the levels steadily declined, reaching a mean titer of 0 log at 20 days. The half-life of the maternally derived antibodies against DHAV was 3.4 ± 1.1 days. Our vaccination strategy might be effective in breeder ducks because it can be easily applied and induced strong immunity. Moreover, our results might provide a foundation for the mechanistic study of maternally derived antibodies in passive protection.
鸭Ⅰ型病毒性肝炎是一种在雏鸭中迅速传播的致死性感染，由鸭肝炎 A 病毒（DHAV）引起。给种鸭接种疫苗是控制 DHAV 的常见做法。然而，在大型鸭群中维持适当的母源抗体水平是困难的。因此，需要一种简单的疫苗接种策略，可以通过大规模接种来诱导稳定的高抗体水平。我们评估了一种种鸭的 DHAV 疫苗接种策略，包括在野外条件下口服接种，并检查了鸭及其后代的抗体反应动力学。该策略包括肌肉内初次接种，然后进行二次和三次口服接种。初次接种后 5 周，病毒中和抗体滴度增加了 8.4±1.3 对数。在长达 36 周的时间里，抗体滴度稳定在 9.0±1.1 对数左右。当在 1、7 或 14 日龄时用强毒 DHAV 对其后代进行攻毒时，没有一只后代死亡。母源抗体从种鸭向其后代的传递率为 12.8±3.0%。当从孵化当天到 20 天测量后代的抗体水平时，抗体水平稳步下降，在 20 天时达到平均 0 对数滴度。DHAV 母源抗体的半衰期为 3.4±1.1 天。我们的疫苗接种策略可能对种鸭有效，因为它易于应用并能诱导强烈的免疫力。此外，我们的结果可能为母源抗体在被动保护中的机制研究提供基础。
