Route of vaccine administration has a great impact on immunization and protection outcomes in chickens. This study was conducted to compare the effect of different administration routes on the efficacy of a thermoresistant Newcastle disease (ND) vaccine (ND.TR.IR) in chickens. A total of 100 one-day-old specific pathogen-free chicks were divided into five groups (n = 20 chicks per group) and vaccinated through different routes at 10 and 20 days of age. Treatments included no vaccination (control [C]), 1 dose inoculation through eye drop (ED), 1 dose inoculation through drinking water (DW), 1 dose inoculation through feed (FV₁), and 10 doses inoculation through feed (FV₁₀). At 20 and 34 days of age, antibody titers were measured against ND virus (NDV) in all the chickens by hemagglutination inhibition (HI) test. Chicks immunized with ND.TR.IR vaccine through different routes of administration also were intramuscularly challenged with a local virulent NDV (vNDV) (Ck/ir/Beh/2011) 14 days after booster vaccination (at 34 days of age). Our results showed that in comparison with the FVs groups, the immunized chicks through ED induced a higher HI antibody titers at 20 days of age (p < 0.05). Meanwhile, vaccination through ED induced higher HI antibody titers at day 34 of age compared with all other groups (p > 0.05). The percentages of the protective HI antibody titers (≥log₂³) detected in ED and DW groups at 20 days of age were higher than those detected in the FV₁ group (p < 0.05). However, routes of vaccination had no significant effect on the rate of protective titers at day 34 of age (100%, 90%, 75%, and 85% for ED, DW, FV₁, and FV₁₀, respectively). The percentage of post-NDV challenge survived chickens was not affected by the route of vaccination (p > 0.05), but immunization of chicks with ND.TR.IR in FV₁ group provided relatively poorer protection when compared with the other groups (90% vs. 100%, respectively). Altogether, immunization of chicks with ND.TR.IR vaccine through different routes of administration induced protective NDV antibody HI titers, and provided protection against vNDV. However, when the vaccine was administrated through feed, a higher dose of vaccine is recommended.

中文翻译：

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不同给药途径对鸡新城疫耐热疫苗功效的影响比较。

疫苗接种途径对鸡的免疫和保护效果有很大影响。进行这项研究的目的是比较不同给药途径对鸡新城疫（ND）疫苗（ND.TR.IR）的功效的影响。将总共​​100只1日龄无病原体的小鸡分为5组（每组n  = 20只小鸡），并在10和20日龄时通过不同途径接种。治疗方法包括不接种疫苗（对照[C]），通过眼药水（ED）接种1剂疫苗，通过饮用水（DW）接种1剂疫苗，通过饲料（FV ₁）接种剂₁和通过饲料（FV ₁₀接种剂）10剂接种。）。在20和34天龄时，通过血凝抑制（HI）测试在所有鸡中测量了针对ND病毒（NDV）的抗体效价。在加强疫苗接种后第14天（年龄为34天），通过不同的给药途径用ND.TR.IR疫苗免疫的小鸡也受到了局部强毒NDV（vNDV）（Ck / ir / Beh / 2011）的肌内攻击。我们的结果表明，与FVs组相比，通过ED免疫的雏鸡在20日龄时诱导出更高的HI抗体滴度（p  <0.05）。同时，与所有其他组相比，在第34天时通过ED接种诱导的HI抗体滴度更高（p  > 0.05）。保护HI抗体滴度的百分数（≥log ₂ ³ED和DW组在20天龄时检测到的）高于FV ₁组中检测到的（p  <0.05）。但是，接种途径对34岁时的保护效价率没有明显影响（ED，DW，FV ₁和FV ₁₀分别为100％，90％，75％和85％）。NDV攻击后存活的鸡的百分比不受疫苗接种途径的影响（p  > 0.05），但在FV ₁中用ND.TR.IR免疫小鸡与其他组相比，该组提供的保护相对较差（分别为90％和100％）。总之，通过不同的给药途径用ND.TR.IR疫苗免疫小鸡会诱导NDV保护性HI滴度，并提供针对vNDV的保护。但是，当通过饲料施用疫苗时，建议使用更高剂量的疫苗。