2- and 3-dose combined hepatitis A and B vaccination imparts immunity for ≥15 years.
All subjects remained seropositive for anti-HAV; 81% were protected for anti-HBs.
One-month post-challenge, all except one subject in the 3-dose group showed a robust anamnestic response.
High anamnestic response suggests no need for booster dosing for ≥15 years.