title: Evaluation of avian influenza virus isolated from ducks as a potential live vaccine candidate against novel H7N9 viruses.
abstract: Recent outbreaks of a novel H7N9 avian influenza virus in humans in China raise pandemic concerns and underscore an urgent need to develop effective vaccines. Theoretically, live influenza vaccines are of multiple advantages over traditional inactivated influenza vaccines to be used in a pandemic, because they can be produced rapidly, safely, and inexpensively. However, studies on live vaccines against the novel H7N9 virus are limited. In this study, we evaluated a potential live influenza vaccine candidate using an H7N3 avian influenza virus isolated from ducks with controls of two recombinant viruses generated through reverse genetics. The potential candidate could be produced efficiently using chicken embryonated eggs, and is homogenous to the novel H7N9 virus in their viral hemagglutinin genes. The potential candidate is likely low pathogenic to birds and mammals, and likely sensitive to oseltamivir and amantadine, as suggested by its genomic sequences. Its low pathogenicity was further supported through inoculation in mice, chicken embryonated eggs and chickens. Specific antibodies elicited in mice were detectable at least during the period between day 14 and day 56 after intranasal administration of the candidate for one time. Titers of the specific antibodies increased significantly with a boost intranasal administration or a higher inoculation dose. The induced specific antibodies were of substantial cross-reactivity with the novel H7N9 virus. These primary but promising evaluation data suggest that the duck influenza virus could be used as a potential live vaccine candidate, favorably through a prime-boost route, to mitigate the severity of the possible pandemic caused by the newly emerging H7N9 virus, and is valuable to be further evaluated.
authors.affiliation: China Animal Health and Epidemiology Center, Qingdao, PR China.
authors.forename: Wen-Ming
authors.initials: WM
authors.lastname: Jiang
authors.affiliation: China Animal Health and Epidemiology Center, Qingdao, PR China.
authors.forename: Su-Chun
authors.initials: SC
authors.lastname: Wang
authors.affiliation: China Animal Health and Epidemiology Center, Qingdao, PR China.
authors.forename: Hua-Lei
authors.initials: HL
authors.lastname: Liu
authors.affiliation: China Animal Health and Epidemiology Center, Qingdao, PR China.
authors.forename: Jian-Min
authors.initials: JM
authors.lastname: Yu
authors.affiliation: China Animal Health and Epidemiology Center, Qingdao, PR China.
authors.forename: Xiang
authors.initials: X
authors.lastname: Du
authors.affiliation: China Animal Health and Epidemiology Center, Qingdao, PR China.
authors.forename: Guang-Yu
authors.initials: GY
authors.lastname: Hou
authors.affiliation: China Animal Health and Epidemiology Center, Qingdao, PR China.
authors.forename: Jin-Ping
authors.initials: JP
authors.lastname: Li
authors.affiliation: China Animal Health and Epidemiology Center, Qingdao, PR China.
authors.forename: Shuo
authors.initials: S
authors.lastname: Liu
authors.affiliation: China Animal Health and Epidemiology Center, Qingdao, PR China.
authors.forename: Kai-Cheng
authors.initials: KC
authors.lastname: Wang
authors.affiliation: China Animal Health and Epidemiology Center, Qingdao, PR China.
authors.forename: Qing-Ye
authors.initials: QY
authors.lastname: Zhuang
authors.affiliation: China Animal Health and Epidemiology Center, Qingdao, PR China.
authors.forename: Xiang-Ming
authors.initials: XM
authors.lastname: Liu
authors.affiliation: China Animal Health and Epidemiology Center, Qingdao, PR China. Electronic address: chenjiming@cahec.cn.
authors.forename: Ji-Ming
authors.initials: JM
authors.lastname: Chen
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D002645:Chickens; D003429:Cross Reactions; D004372:Ducks / Q000821:virology*; D005260:Female; D006385:Hemagglutination Inhibition Tests; D053124:Influenza A Virus, H5N1 Subtype; D057920:Influenza A Virus, H7N3 Subtype; D064766:Influenza A Virus, H7N9 Subtype / Q000145:classification / Q000302:isolation & purification*; D007252:Influenza Vaccines / Q000276:immunology*; D005585:Influenza in Birds / Q000517:prevention & control*; D051379:Mice; D008807:Mice, Inbred BALB C; D009500:Neutralization Tests; D009976:Orthomyxoviridae Infections / Q000276:immunology; D010802:Phylogeny; D016865:Reassortant Viruses / Q000235:genetics
chemical_list: D000914:Antibodies, Viral; D007252:Influenza Vaccines
keywords: Antibody; Avian influenza virus; H7N9; Live vaccine; Pandemic