title: A randomized clinical trial of an inactivated avian influenza A (H7N7) vaccine.
abstract: BACKGROUND
  Concern for a pandemic caused by a newly emerged avian influenza A virus has led to clinical trials with candidate vaccines as preparation for such an event. Most trials have involved vaccines for influenza A (H5N1), A (H7N7) or A (H9N2).
  
  
  OBJECTIVE
  To evaluate dosage-related safety and immunogenicity of an inactivated influenza A (H7N7) vaccine in humans.
  
  
  METHODS
  One hundred twenty-five healthy young adults were randomized to receive two doses intramuscularly of placebo or 7.5, 15, 45 or 90 µg of HA of an inactivated subunit influenza A (H7N7) vaccine (25 per group), four weeks apart. Reactogenicity was evaluated closely for one week and for any adverse effect for six months after each dose. Serum hemagglutination-inhibiting and neutralizing antibody responses were determined four weeks after each dose and at six months.
  
  
  RESULTS
  Reactogenicity evaluations indicated the vaccinations were well tolerated. Only one subject developed a ≥4-fold serum hemagglutination-inhibition (HAI) antibody response and a final titer of ≥1:40 four weeks after dose two and only five subjects developed a neutralizing antibody rise and a final titer of ≥1:40 in tests performed at a central laboratory. Four of the five were given the 45 or 90 µg HA dosage. A more sensitive HAI assay at the study site revealed a dose-response with increasing HA dosage but only 36% in the 90 µg HA group developed a ≥4-fold rise in antibody in this test and only one of these achieved a titer of ≥1:32.
  
  
  CONCLUSIONS
  This inactivated subunit influenza A (H7N7) vaccine was safe but poorly immunogenic in humans.
  
  
  BACKGROUND
  ClinicalTrials.gov NCT00546585.
authors.affiliation: Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas, United States of America. rcouch@bcm.edu
authors.forename: Robert B
authors.initials: RB
authors.lastname: Couch
authors.forename: Shital M
authors.initials: SM
authors.lastname: Patel
authors.forename: Chianti L
authors.initials: CL
authors.lastname: Wade-Bowers
authors.forename: Diane
authors.initials: D
authors.lastname: Niño
mesh_terms: D000293:Adolescent; D000328:Adult; D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D000917:Antibody Formation / Q000276:immunology; D001717:Birds / Q000276:immunology / Q000821:virology; D005260:Female; D006801:Humans; D053126:Influenza A Virus, H7N7 Subtype / Q000276:immunology / Q000472:pathogenicity; D007252:Influenza Vaccines / Q000008:administration & dosage* / Q000009:adverse effects; D005585:Influenza in Birds / Q000276:immunology / Q000517:prevention & control; D007251:Influenza, Human / Q000276:immunology / Q000517:prevention & control; D008297:Male; D015164:Vaccines, Inactivated / Q000008:administration & dosage* / Q000009:adverse effects
chemical_list: D000914:Antibodies, Viral; D007252:Influenza Vaccines; D015164:Vaccines, Inactivated