title: Cross-clade protective immunity of H5N1 influenza vaccines in a mouse model.
abstract: H5N1 highly pathogenic avian influenza viruses evolved into several clades, leading to appreciably distinct antigenicities of their hemagglutinins. As such, candidate H5N1 pre-pandemic vaccines for human use should be sought. Here, to evaluate fundamental immunogenic variations between H5N1 vaccines, we prepared four inactivated H5N1 test vaccines from different phylogenetic clades (clade 1, 2.1, 2.2, and 2.3.4) in accordance with the WHO recommendation, and tested their cross-clade immunity in a mouse model by vaccination followed by challenge with heterologous virulent viruses. All H5N1 vaccines tested provided full or partial cross-clade protective immunity, except one clade 2.2-based vaccine, which did not protect mice from clade 2.3.4 virus challenge. Among the test vaccines, a clade 2.1-based vaccine possessed the broadest-spectrum cross-immunity. These results suggest that currently stockpiled pre-pandemic vaccines, especially clade 2.1-based vaccines, will likely be useful as backup vaccines in a pandemic situation, even one involving antigenic-drifted viruses.
authors.affiliation: Division of Virology, Department of Microbiology and Immunology, Institute of Medical Science, University of Tokyo, Tokyo, Japan.
authors.forename: Shin
authors.initials: S
authors.lastname: Murakami
authors.forename: Ayaka
authors.initials: A
authors.lastname: Iwasa
authors.forename: Kiyoko
authors.initials: K
authors.lastname: Iwatsuki-Horimoto
authors.forename: Mutsumi
authors.initials: M
authors.lastname: Ito
authors.forename: Maki
authors.initials: M
authors.lastname: Kiso
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kida
authors.forename: Ayato
authors.initials: A
authors.lastname: Takada
authors.forename: Chairul A
authors.initials: CA
authors.lastname: Nidom
authors.forename: Le Quynh
authors.initials: le Q
authors.lastname: Mai
authors.forename: Shinya
authors.initials: S
authors.lastname: Yamada
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Imai
authors.forename: Yuko
authors.initials: Y
authors.lastname: Sakai-Tagawa
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Kawaoka
authors.forename: Taisuke
authors.initials: T
authors.lastname: Horimoto
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000096:biosynthesis / Q000276:immunology*; D003429:Cross Reactions / Q000276:immunology*; D004195:Disease Models, Animal; D005260:Female; D006801:Humans; D007109:Immunity; D053124:Influenza A Virus, H5N1 Subtype / Q000145:classification / Q000235:genetics / Q000276:immunology*; D007252:Influenza Vaccines / Q000008:administration & dosage / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D009976:Orthomyxoviridae Infections / Q000276:immunology / Q000517:prevention & control* / Q000821:virology
chemical_list: D000914:Antibodies, Viral; D007252:Influenza Vaccines