Abstract：
With the improvement of large-scale breeding in pig farms, conventional head-by-head immunization has disadvantages with low efficiency and high cost. Considering that most pathogens leading to pulmonary diseases circulate from the respiratory mucosa, immunization through the respiratory tract route has been a highly attractive vaccine delivery strategy. In this study, to develop an effective Mycoplasma hyopneumoniae (Mhp) aerosol vaccine, a customized ultrasonic atomizer was developed. The aerodynamic diameter, activity, and content of the Mhp aerosol vaccine were measured. In addition, piglets were immunized with the Mhp aerosol vaccine, and the immunity of the animal challenge protection test was evaluated. At the end of nebulization, the mass median aerodynamic diameters (MMAD) and geometric standard deviation (GSD) of the aerosol were 2.98 ± 0.02 μm and 1.51 ± 0.02, respectively. Moreover, 10 min after nebulization, the MMAD and GSD of the aerosol were 2.76 ± 0.02 μm and 1.51 ± 0.01, respectively, which were hardly changed. Compared with theoretical value, the actual titer of aerosol vaccines presented in 50% color changing unit (CCU50) after nebulization decreased 0.6. The shape, size, and uniformity of collected aerosols are relatively stable. The proportion of Mhp in aerosol produced by vaccine stock solution and 10 times diluted vaccine solution was 76.52% and 58.82%, respectively, and the average number of Mhp in a single aerosol was 3.06 and 1.51, respectively. In addition, the aerosol vaccine antigen particles could be transported to the lower respiratory tract, a local mucosal immune response was induced in piglets. The vaccine colonized the respiratory tract and significantly decline the lung lesion index after aerosol vaccination. In conclusion, an effective aerosol vaccine against Mhp infection was developed. And this is the first effective assessment for Mhp live vaccine with aerosolization against infection in piglets.
摘要：
随着猪场规模化养殖的完善,传统的头部免疫具有效率低、成本高的缺点。考虑到大多数导致肺部疾病的病原体是从呼吸道粘膜循环的，通过呼吸道途径进行免疫是一种非常有吸引力的疫苗递送策略。在这项研究中,开发有效的猪肺炎支原体（Mhp）气溶胶疫苗，开发了定制的超声波雾化器。空气动力学直径，活动,并测定Mhp气溶胶疫苗的含量。此外,用Mhp气溶胶疫苗免疫仔猪，并对动物攻击保护试验的免疫力进行评价。雾化结束时，气溶胶的质量中值空气动力学直径（MMAD）和几何标准偏差（GSD）分别为2.98±0.02μm和1.51±0.02。此外，雾化后10分钟，气溶胶的MMAD和GSD分别为2.76±0.02μm和1.51±0.01,几乎没有改变。与理论值相比，雾化后,以50%变色单位(CCU50)显示的气溶胶疫苗的实际滴度下降了0.6.形状,尺寸,收集的气溶胶的均匀性相对稳定。疫苗原液和10倍稀释疫苗溶液产生的气溶胶中Mhp的比例分别为76.52%和58.82%,分别,单个气溶胶中Mhp的平均数分别为3.06和1.51。此外,气溶胶疫苗抗原颗粒可以转运到下呼吸道，在仔猪中诱导局部粘膜免疫应答。该疫苗定植于呼吸道，气雾剂接种后肺部病变指数显著下降。总之,开发了针对Mhp感染的有效气溶胶疫苗。这是对Mhp活疫苗雾化抗仔猪感染的首次有效评估。
