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. Aim: To examine the efficacy of a 12-month dosing interval for two-dose hepatitis B vaccination of adolescents. Subjects: Four hundred and fifty-eight healthy first-year high school (Year 7) students. Vaccination regimen: Engerix-B (GlaxoSmithKline Biologicals) 20 μg: 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 ≥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). Conclusion: A high seroprotection rate and GMC were achieved using two 20 μg 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.