title: A live attenuated vaccine prevents replication and transmission of H7N9 virus in mammals.
abstract: The continued spread of the newly emerged H7N9 viruses among poultry in China, together with the emergence of drug-resistant variants and the possibility of human-to-human transmission, has spurred attempts to develop an effective vaccine. An MF59-adjuvant H7N9 inactivated vaccine is reported to be well-tolerated and immunogenic in humans; however a study in ferrets indicated that while a single dose of the inactivated H7N9 vaccine reduced disease severity, it did not prevent virus replication and transmission. In this study, we used reverse genetics to produce a cold-adapted, live attenuated H7N9 vaccine (H7N9/AAca) that contains wild-type HA and NA genes from AH/1, and the backbone of the cold-adapted influenza H2N2 A/Ann Arbor/6/60 virus (AAca). H7N9/AAca was attenuated in mice and ferrets, and induced robust neutralizing antibody responses in rhesus mice, ferrets, and guinea pigs immunized once or twice intranasally. The animals immunized twice were completely protected from H7N9 virus challenge. Importantly, the animals vaccinated once were fully protected from transmission when exposed to or in contact with the H7N9 virus-inoculated animals. These results demonstrate that a cold-adapted H7N9 vaccine can prevent H7N9 virus transmission; they provide a compelling argument for further testing of this vaccine in human trials.
authors.affiliation: State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150001, People's Republic of China.
authors.forename: Huihui
authors.initials: H
authors.lastname: Kong
authors.affiliation: 1] State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150001, People's Republic of China [2] Department of Inspection Technology Research &National Classical Swine Fever Reference Laboratory, China Institute of Veterinary Drug Control, Beijing 100081, People's Republic of China.
authors.forename: Qianyi
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150001, People's Republic of China.
authors.forename: Chunyang
authors.initials: C
authors.lastname: Gu
authors.affiliation: State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150001, People's Republic of China.
authors.forename: Jianzhong
authors.initials: J
authors.lastname: Shi
authors.affiliation: State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150001, People's Republic of China.
authors.forename: Guohua
authors.initials: G
authors.lastname: Deng
authors.affiliation: State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150001, People's Republic of China.
authors.forename: Shujie
authors.initials: S
authors.lastname: Ma
authors.affiliation: State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150001, People's Republic of China.
authors.forename: Jinxiong
authors.initials: J
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150001, People's Republic of China.
authors.forename: Pucheng
authors.initials: P
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150001, People's Republic of China.
authors.forename: Yuntao
authors.initials: Y
authors.lastname: Guan
authors.affiliation: State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150001, People's Republic of China.
authors.forename: Yongping
authors.initials: Y
authors.lastname: Jiang
authors.affiliation: State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150001, People's Republic of China.
authors.forename: Hualan
authors.initials: H
authors.lastname: Chen
mesh_terms: D000818:Animals; D064766:Influenza A Virus, H7N9 Subtype / Q000276:immunology / Q000502:physiology*; D014613:Vaccines, Attenuated / Q000276:immunology*; D014779:Virus Replication / Q000276:immunology*
chemical_list: D014613:Vaccines, Attenuated