title: Immune response to a new hepatitis B vaccine in healthcare workers who had not responded to standard vaccine: randomised double blind dose-response study.
abstract: OBJECTIVE
  To evaluate the immunogenicity and reactogenicity of a new triple S recombinant hepatitis B vaccine in a cohort of healthy people in whom currently licensed hepatitis B vaccines had persistently not induced an immune response.
  
  
  METHODS
  Single centre, randomised, double blind, dose-response study.
  
  
  METHODS
  Research vaccine evaluation centre at a teaching hospital.
  
  
  METHODS
  100 healthcare workers aged 18-70 years with a history of failure to seroconvert after at least four doses of a licensed hepatitis B vaccine containing the S component.
  
  
  METHODS
  Each subject was randomly allocated two doses of 5, 10, 20, or 40 micrograms of a new hepatitis B vaccine two months apart.
  
  
  METHODS
  Immunogenicity of the four doses. Seroconversion and seroprotection were defined as an antibody tire > 10 IU/l and > 100 IU/l respectively against an international antibody standard.
  
  
  RESULTS
  69 subjects seroconverted after a single dose of the vaccine. After the booster vaccination one other subject seroconverted, bringing the overall seroconversion rate to 70%. Fifteen subjects given 5 micrograms of vaccine, 19 given 10 micrograms, 16 given 20 micrograms, and 20 given 40 micrograms seroconverted. Seroconversion rates in the four antigen dose groups were 60% (15/25), 76% (19/25), 64% (16/25), and 80% (20/25). After the booster dose there was no significant dose-response effect on the overall seroconversion rate, although the small sample size meant that a clinically important dose-response could not be ruled out.
  
  
  CONCLUSIONS
  A single dose of 20 micrograms of the vaccine was as effective as two doses of either 40 micrograms or 20 micrograms of this vaccine formulation in terms of seroconversion, seroprotection, and geometric mean titres.
authors.affiliation: Academic Unit of Travel Medicine and Vaccines, Royal Free Hospital School of Medicine, London.
authors.forename: J N
authors.initials: JN
authors.lastname: Zuckerman
authors.forename: C
authors.initials: C
authors.lastname: Sabin
authors.forename: F M
authors.initials: FM
authors.lastname: Craig
authors.forename: A
authors.initials: A
authors.lastname: Williams
authors.forename: A J
authors.initials: AJ
authors.lastname: Zuckerman
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000917:Antibody Formation; D015331:Cohort Studies; D004306:Dose-Response Relationship, Immunologic; D004311:Double-Blind Method; D005260:Female; D006282:Health Personnel; D006509:Hepatitis B / Q000276:immunology / Q000517:prevention & control*; D006514:Hepatitis B Surface Antigens / Q000276:immunology*; D017325:Hepatitis B Vaccines / Q000276:immunology*; D006801:Humans; D007117:Immunization, Secondary; D008297:Male; D008875:Middle Aged; D016273:Occupational Exposure / Q000517:prevention & control*; D017410:Practice Guidelines as Topic; D014611:Vaccination
chemical_list: D006514:Hepatitis B Surface Antigens; D017325:Hepatitis B Vaccines