Objective To supply science basis for improving on immune strategy of heptitis A vaccine, and to understand epidemiology of heptitis A in Hongkou since vaccinating heptitis A vaccine.

• 目的为了解接种甲肝疫苗以来虹口区甲型肝炎流行病学特征，为改进甲肝疫苗免疫策略提供依据。