接种乙肝疫苗是目前预防乙型肝炎的有效手段。2003年6月,济南大学某班学生在接种乙肝疫苗3a后复发多起乙肝感染,现将流行病学调查结果报道如下。1 流行病学调查1.1 基本情况济南大学1999级新生于入校1周内,经健康查体,化验肝功能正常,乙肝表面抗原阴性者,均接种乙肝疫苗。某班共有学生57人,肝功能均正常,有1人HBsAg呈阳性 Hepatitis B vaccination is an effective way to prevent hepatitis B. June 2003, Jinan University, a class of students vaccinated hepatitis B vaccine 3a relapse after more hepatitis B infection, the epidemiological findings are reported below. 1 epidemiological survey 1.1 The basic situation Jinan University, 1999 freshmen in the school within 1 week, the physical examination, liver function tests normal, hepatitis B surface antigen-negative, were vaccinated against hepatitis B vaccine. A total of 57 students in a class, liver function were normal, one positive HBsAg