title: A novel hepatitis B vaccination regimen for adolescents: two doses 12 months apart.
abstract: BACKGROUND
  Two- and three-dose hepatitis B vaccinations for adolescents are usually administered using dosing schedules of 6 months duration. This does not suit all circumstances. A 12-month schedule would be useful in schools and settings where only annual vaccination is the most practical option.
  
  
  OBJECTIVE
  To examine the efficacy of a 12-month dosing interval for two-dose hepatitis B vaccination of adolescents.
  
  
  METHODS
  Four hundred and fifty-eight healthy first-year high school (Year 7) students. VACCINATION REGIMEN: Engerix-B (GlaxoSmithKline Biologicals) 20 micro g: two doses, 12 months apart. SERUM COLLECTION: #1, same day as first vaccine dose given; #2, >1 month after second vaccine dose.
  
  
  RESULTS
  Of the 458 children: 15 did not provide serum #1, 17 had prior vaccination, 2 had prior infection, 18 moved, 7 failed to provide serum #2, 12 withdrew (only 1 cited vaccine adverse reactions as the reason). Three hundred and eighty-seven (210 males, 177 females) aged 11.8-14.2 years (mean: 12.9+/-0.42 years) at entry completed both injections 321-381 days (mean: 359+/-10.7 days) apart and supplied serum #2, 30-57 days (mean: 41+/-5.6 days) after the second vaccine dose.Anti-HBs responses: 379 of the 387 subjects (97.9%; 95% CI: 95.9-99.1%) achieved anti-HBs > or =10 mIU/ml (range 10-170,460 mIU/ml, geometric mean concentration (GMC) 4155 mIU/ml-95% CI of mean: 3381-5106 mIU/ml). Sex was the only determinant of anti-HBs concentration (206 males: GMC 3073 mIU/ml-95% CI: 2285-4134 mIU/ml; 173 females: GMC 5944 mIU/ml-95% CI: 4508-7851 mIU/ml; P=0.001).
  
  
  CONCLUSIONS
  A high seroprotection rate and GMC were achieved using two 20 micro g doses of Engerix-B administered 12 months apart. These results are similar to those achieved by others using 6-month three- and two-dose regimens in adolescents.
authors.affiliation: South Western Sydney Public Health Unit, Liverpool Hospital, Locked Bag 7017, NSW 1871, Sydney, Australia. leon.heron@swsahs.nsw.gov.au
authors.forename: Leon G
authors.initials: LG
authors.lastname: Heron
authors.forename: Kerry G
authors.initials: KG
authors.lastname: Chant
authors.forename: Bin B
authors.initials: BB
authors.lastname: Jalaludin
mesh_terms: D000293:Adolescent; D002648:Child; D005260:Female; D006510:Hepatitis B Antibodies / Q000097:blood; D017325:Hepatitis B Vaccines / Q000008:administration & dosage* / Q000009:adverse effects / Q000276:immunology; D006801:Humans; D007115:Immunization Schedule; D008297:Male; D014611:Vaccination
chemical_list: D006510:Hepatitis B Antibodies; D017325:Hepatitis B Vaccines