title: Development and validation of an attenuated Mycoplasma hyopneumoniae aerosol vaccine.
abstract: 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.
authors.affiliation: 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. Electronic address: zhixinf2000@gmail.com.
authors.forename: Zhi-Xin
authors.initials: ZX
authors.lastname: Feng
authors.forename: Yan-Na
authors.initials: YN
authors.lastname: Wei
authors.forename: Gui-Lan
authors.initials: GL
authors.lastname: Li
authors.forename: Xiao-Ming
authors.initials: XM
authors.lastname: Lu
authors.forename: Xiu-Feng
authors.initials: XF
authors.lastname: Wan
authors.forename: G Todd
authors.initials: GT
authors.lastname: Pharr
authors.forename: Zhan-Wei
authors.initials: ZW
authors.lastname: Wang
authors.forename: Meng
authors.initials: M
authors.lastname: Kong
authors.forename: Yuan
authors.initials: Y
authors.lastname: Gan
authors.forename: Fang-Fang
authors.initials: FF
authors.lastname: Bai
authors.forename: Mao-Jun
authors.initials: MJ
authors.lastname: Liu
authors.forename: Qi-Yan
authors.initials: QY
authors.lastname: Xiong
authors.forename: Xu-Su
authors.initials: XS
authors.lastname: Wu
authors.forename: Guo-Qing
authors.initials: GQ
authors.lastname: Shao
mesh_terms: D000336:Aerosols; D000818:Animals; D001428:Bacterial Vaccines / Q000008:administration & dosage*; D006813:Humidity; D007071:Immunoglobulin A, Secretory / Q000378:metabolism; D008855:Microscopy, Electron, Scanning; D045705:Mycoplasma hyopneumoniae; D010316:Particle Size; D045729:Pneumonia of Swine, Mycoplasmal / Q000517:prevention & control*; D012137:Respiratory System / Q000378:metabolism / Q000648:ultrastructure; D013552:Swine; D013696:Temperature; D014611:Vaccination / Q000379:methods / Q000662:veterinary*; D064166:Vaccine Potency; D014613:Vaccines, Attenuated / Q000008:administration & dosage
chemical_list: D000336:Aerosols; D001428:Bacterial Vaccines; D007071:Immunoglobulin A, Secretory; D014613:Vaccines, Attenuated
keywords: Aerosol vaccine; Attenuated aerosol vaccine; Mycoplasma hyopneumoniae; Nebulization