Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences, Key Laboratory of Veterinary Biological Engineering and Technology, Ministry of Agriculture, National Research Center for Engineering and Technology of Veterinary Bio-products, Nanjing 210014, China.
Vet Microbiol. 2013 Dec 27;167(3-4):417-24. doi: 10.1016/j.vetmic.2013.08.012. Epub 2013 Aug 28.
Mycoplasma hyopneumoniae (M. hyopneumoniae) causes a chronic respiratory disease with high morbidity and low mortality in swine, and has been presented as a major cause of growth retardation in the swine industry. Aerosol vaccination presents a needle free, high throughput, and efficient platform for vaccine delivery, and has been widely applied in poultry vaccination. However, aerosol vaccines have rarely been used in swine vaccination primarily because the long and curving respiratory track of swine presents a barrier for vaccine particle delivery. To develop an effective M. hyopneumoniae aerosol vaccine, three major barriers need to be overcome: to optimize particle size for aerosol delivery, to maintain the viability of mycoplasma cells in the vaccine, and to optimize the environmental conditions for vaccine delivery. In this study, an aerosol mycoplasma vaccine was successfully developed based on a conventional live attenuated M. hyopneumoniae vaccine. Specifically, the Pari LCD nebulizer was used to produce an aerosol vaccine particle size less than 5 μm; and a buffer with 5% glycerol was developed and optimized to prevent inactivation of M. hyopneumoniae caused by aerosolization and evaporation. Before nebulization, the room temperature and relative humidity were control to 20-25 °C and 70-75%, respectively, which helped maintain the viability of aerosol vaccine. Animal experiments demonstrated that this newly developed aerosol vaccine was effectively delivered to swine low respiratory track, being confirmed by nested-PCR, in situ hybridization and scanning electron microscope. Moreover, M. hyopneumoniae specific sIgA secretion was detected in the nasal swab samples at 14 days post-immunization. To our knowledge, this is the first report on a live M. hyopneumoniae aerosol vaccine.
猪肺炎支原体（M. hyopneumoniae）引起的慢性呼吸道疾病在猪中发病率高、死亡率低，已成为猪养殖业生长迟缓的主要原因。气溶胶疫苗接种提供了一种无针、高通量、高效的疫苗输送平台，已广泛应用于家禽疫苗接种。然而，气溶胶疫苗在猪疫苗接种中很少使用，主要是因为猪的长而弯曲的呼吸道对疫苗颗粒输送构成了障碍。为了开发有效的猪肺炎支原体气溶胶疫苗，需要克服三个主要障碍：优化用于气溶胶输送的颗粒大小、保持疫苗中支原体细胞的活力以及优化疫苗输送的环境条件。在这项研究中，成功地基于常规的活减毒猪肺炎支原体疫苗开发了一种气溶胶支原体疫苗。具体而言，使用 Pari LCD 雾化器产生小于 5μm 的气溶胶疫苗颗粒；并开发和优化了含有 5%甘油的缓冲液，以防止气溶胶化和蒸发导致猪肺炎支原体失活。在雾化之前，将室温控制在 20-25°C，相对湿度控制在 70-75%，这有助于保持气溶胶疫苗的活力。动物实验表明，这种新开发的气溶胶疫苗有效地递送到猪的下呼吸道，通过巢式 PCR、原位杂交和扫描电子显微镜得到证实。此外，在免疫后 14 天，在鼻拭子样本中检测到了猪肺炎支原体特异性 sIgA 分泌。据我们所知，这是第一个关于活猪肺炎支原体气溶胶疫苗的报告。
