 The study evaluated the persistence of protection from hepatitis B, HB, vaccination among adolescents immunized with a primary series of HB vaccine as infants and the immune response to booster doses. It found that vaccine-induced immunity persisted for up to 15 to 17 y in 89.3 percent of participants after a primary HB vaccination in infancy and administering a booster dose of 20 ghb vaccine elicited an amnestic immune response in the majority of individuals with baseline anti-HPS less than 10 mIU ML. This article was offered by Zhenzi Wang, Yuhua G.A.O, Weilu, and others.