In September 1999, Merck Vaccine Division (Merck & Co., Inc., West Point, Pennsylvania*) received approval from the Food and Drug Administration for an optional two-dose schedule of Recombivax HB® for vaccination of adolescents aged 11-15 years. The Advisory Committee on Immunization Practices approved the optional two-dose schedule in October 1999 and recommended to include this schedule in the Vaccines for Children Program in February 2000. Using the two-dose schedule, the adult dose of Recombivax HB® (1.0 mL dose containing 10 microgram of hepatitis B surface antigen [HBsAg]) is administered to adolescents aged 11-15 years, with the second dose given 4-6 months after the first dose. In immunogenicity studies among adolescents aged 11-15 years, antibody concentrations and end seroprotection rates (greater than or equal to 10 milli-international units per mL of antibody to HBsAg) were similar with the two-dose schedule (1.0 mL dose containing 10 microgram of HBsAg) and the currently licensed three-dose schedule (0.5 mL dose containing 5 microgram of HBsAg). The overall frequency of adverse events was similar for the two-dose schedule and the three-dose schedule. Short-term (2-year) follow-up data indicate that the rate of decline in antibody levels for the two-dose schedule was similar to that for the three-dose schedule. No data are available to assess long-term protection (beyond 2 years) or immune memory following vaccination with the two-dose schedule, and it is not known whether booster doses of vaccine will be required. As with other hepatitis B vaccination schedules, if administration of the two-dose schedule is interrupted it is not necessary to restart the series. Children and adolescents who have begun vaccination with a dose of 5 microgram of Recombivax HB® should complete the three-dose series with this dose. If it is not clear which dose an adolescent was administered at the start of a series, the series should be completed with the three-dose schedule.
Alternate Two-Dose Hepatitis B Vaccination Schedule for Adolescents Aged 11-15 Years. JAMA. 2000;283(16):2100. doi:10.1001/jama.283.16.2100-JWR0426-4-1