1　背景预防接种与卫生和环境卫生一同促进着全球每个国家中儿童的健康,每年从死亡线上挽救着数以百万的儿童,大大降低了因感染传染病而导致的残障。今天,计划免疫成为促进健康的最经济有效的方法之一,也为其它影响健康的干预措施,如补充营养和预防疟疾的实施提供了机会。然而 1 Background Vaccination, together with health and sanitation, contributes to the health of children in every country in the world, saving millions of children each year online from death lines and greatly reducing the number of disability resulting from the transmission of infectious diseases. Today, planned immunization is one of the most cost-effective ways to promote health and offers opportunities for other health-affecting interventions, such as nutrition supplementation and the prevention of malaria. however