In this study, immunogenic efficacies of in ovo administration of Astragalus polysaccharide (APS) along with live Newcastle disease vaccine (live ND vaccine) (live VG/GA strain) were evaluated. Four hundred fertilized eggs were randomly divided into four groups (n = 100/group), and vaccinated in ovo, respectively, with solutions of APS, live ND vaccine, live ND vaccine combined with APS, and 0.9% physiological saline into their amniotic fluid on d 18.5 of incubation. Significant improvement of chicks’ development was displayed in those vaccinated with live ND vaccine adjuvanted with APS in ovo, manifested as enhanced hatchability and gaining weight. Moreover, in ovo administration of live NDV vaccine plus APS could significantly enhance the serum anti‐NDV antibody titres and interferon gamma (IFN‐γ), interleukin (IL)‐2, IL‐4 and IL‐6 concentrations, promote lymphocyte proliferative capability as well as improve the frequencies of CD4⁺ and CD8⁺ T cells in peripheral blood. Overall results indicated in ovo administration of live ND vaccine adjuvanted with APS could stimulate stronger humoral and cellular responses in newly hatched chicks.

中文翻译：

---

黄芪多糖对新城疫疫苗卵内注射的免疫佐剂作用。

在这项研究中，评估了黄芪多糖 (APS) 与活新城疫疫苗（活 ND 疫苗）（活 VG/GA 株）一起在卵内给药的免疫原性功效。将400个受精卵随机分为4组（n  =100/组），分别用APS、ND活疫苗、ND活疫苗联合APS溶液和0.9%生理盐水加入羊水进行卵内接种在孵化的第 18.5 天。以卵内APS 为佐剂的 ND 活疫苗接种后，雏鸡的发育有显着改善，表现为孵化率提高和体重增加。此外，在 ovoNDV 活疫苗联合 APS 可显着提高血清抗 NDV 抗体滴度和干扰素 γ（IFN-γ）、白细胞介素（IL）-2、IL-4 和 IL-6 浓度，促进淋巴细胞增殖能力并改善外周血中 CD4 ⁺和 CD8 ⁺ T 细胞的频率。总体结果表明，在卵内施用以 APS 为佐剂的活 ND 疫苗可以在新孵化的小鸡中刺激更强的体液和细胞反应。