Abousenna Mohamed Samy, Shafik Nermeen G, Abotaleb Mahmoud M
Central Laboratory for Evaluation of Veterinary Biologics, Agricultural Research Center, P.O. Box 131, Cairo, 11381, Egypt.
Sci Rep. 2025 Feb 7;15(1):4637. doi: 10.1038/s41598-025-87831-w.
The detection of Highly Pathogenic Avian Influenza (HPAI) A(H5N1) in dairy cattle in the United States has raised concerns about human exposure. This study evaluated the efficacy of various doses of an inactivated H5 AI vaccine in cattle and assessed antibody transfer in milk against a recent bovine isolate of HPAI A(H5N1, clade 2.3.4.4b). Calves were inoculated with different vaccine doses, while lactating cows received the vaccine four weeks later. The humoral immune response was measured using the Hemagglutination Inhibition (HI) test and ELISA. Results showed a dose-dependent immune response, with higher doses producing stronger and more sustained antibody levels. Group 1 maintained a stable HI titer of 6 log, while Groups 2, 3, and 4 peaked at 8, 9, and 9 log, respectively, by the fourth week post-vaccination. Milk antibody transfer was observed, with strong positive responses in milk samples by the second week post-vaccination. The ID Screen ELISA demonstrated higher sensitivity for detecting antibodies in milk compared to serum. The immune response to the AI vaccine differed from responses to other vaccines used in cattle such as Foot and Mouth Disease Virus (FMDV) and Lumpy Skin Disease Virus (LSDV), indicating the need for optimizing vaccine dosage and formulation, including adjuvant and antigen content. Future research should extend the monitoring period, increase sample sizes, and explore different vaccine formulations to develop effective vaccination strategies for cattle. These findings highlight the potential for using inactivated H5 AI vaccines in cattle to enhance immune protection and facilitate antibody transfer through milk.
美国奶牛中检测到高致病性禽流感（HPAI）A（H5N1）引发了人们对人类接触风险的担忧。本研究评估了不同剂量的灭活H5禽流感疫苗对牛的效力，并评估了牛奶中针对最近分离的牛高致病性禽流感A（H5N1，2.3.4.4b分支）的抗体转移情况。给犊牛接种不同剂量的疫苗，而泌乳奶牛在四周后接种疫苗。使用血凝抑制（HI）试验和酶联免疫吸附测定（ELISA）来测量体液免疫反应。结果显示出剂量依赖性免疫反应，较高剂量产生更强且更持久的抗体水平。第1组在接种疫苗后第四周维持稳定的HI效价为6 log，而第2、3和4组分别在接种后第四周达到峰值，效价为8、9和9 log。观察到了牛奶中的抗体转移，接种疫苗后第二周牛奶样本中出现强烈阳性反应。ID Screen ELISA在检测牛奶中的抗体方面比血清具有更高的灵敏度。对禽流感疫苗的免疫反应与牛使用的其他疫苗如口蹄疫病毒（FMDV）和结节性皮肤病病毒（LSDV）的反应不同，这表明需要优化疫苗剂量和配方，包括佐剂和抗原含量。未来的研究应延长监测期、增加样本量并探索不同的疫苗配方，以制定有效的牛疫苗接种策略。这些发现突出了在牛中使用灭活H5禽流感疫苗增强免疫保护并促进通过牛奶进行抗体转移的潜力。
