 The hepatitis A vaccine, Hep A, has been licensed since 1992 and is highly immunogenic, effective for both pre-exposure and post-exposure prophylaxis and can provide immune protection for at least 20 years. The strategy of Hep A vaccination varies among countries, but its use has decreased the incidence of hepatitis A in many countries. Further research is needed to determine the long-term persistence of immune protection after one dose of Hep A and to evaluate cost-effective strategies for vaccination. This article was authored by Li Zhong.