title: Virus-like particle vaccine protects against 2009 H1N1 pandemic influenza virus in mice.
abstract: BACKGROUND
  The 2009 influenza pandemic and shortages in vaccine supplies worldwide underscore the need for new approaches to develop more effective vaccines.
  
  
  RESULTS
  We generated influenza virus-like particles (VLPs) containing proteins derived from the A/California/04/2009 virus, and tested their efficacy as a vaccine in mice. A single intramuscular vaccination with VLPs provided complete protection against lethal challenge with the A/California/04/2009 virus and partial protection against A/PR/8/1934 virus, an antigenically distant human isolate. VLP vaccination induced predominant IgG2a antibody responses, high hemagglutination inhibition (HAI) titers, and recall IgG and IgA antibody responses. HAI titers after VLP vaccination were equivalent to those observed after live virus infection. VLP immune sera also showed HAI responses against diverse geographic pandemic isolates. Notably, a low dose of VLPs could provide protection against lethal infection.
  
  
  CONCLUSIONS
  This study demonstrates that VLP vaccination provides highly effective protection against the 2009 pandemic influenza virus. The results indicate that VLPs can be developed into an effective vaccine, which can be rapidly produced and avoid the need to isolate high growth reassortants for egg-based production.
authors.affiliation: Department of Microbiology and Immunology and Emory Vaccine Center, Emory University School of Medicine, Atlanta, Georgia, United States of America.
authors.forename: Fu-Shi
authors.initials: FS
authors.lastname: Quan
authors.forename: Aswani
authors.initials: A
authors.lastname: Vunnava
authors.forename: Richard W
authors.initials: RW
authors.lastname: Compans
authors.forename: Sang-Moo
authors.initials: SM
authors.lastname: Kang
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D002460:Cell Line; D002642:Chick Embryo; D005260:Female; D006385:Hemagglutination Inhibition Tests; D006388:Hemagglutinins / Q000235:genetics / Q000276:immunology; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007156:Immunologic Memory / Q000276:immunology; D053118:Influenza A Virus, H1N1 Subtype / Q000235:genetics / Q000276:immunology*; D007252:Influenza Vaccines / Q000008:administration & dosage / Q000276:immunology*; D007251:Influenza, Human / Q000821:virology; D051379:Mice; D008807:Mice, Inbred BALB C; D008854:Microscopy, Electron; D009976:Orthomyxoviridae Infections / Q000097:blood / Q000276:immunology* / Q000517:prevention & control; D014611:Vaccination; D014763:Viral Matrix Proteins / Q000235:genetics / Q000276:immunology; D014771:Virion / Q000276:immunology* / Q000648:ultrastructure; D014779:Virus Replication / Q000276:immunology
chemical_list: D000914:Antibodies, Viral; D006388:Hemagglutinins; D007074:Immunoglobulin G; D007252:Influenza Vaccines; C488936:M1 protein, Influenza A virus; D014763:Viral Matrix Proteins