实时疫苗通过复制(1-2周)保护造成组织损伤(1-2周)的持续时间不长(取决于疾病!)Replication and infection of host cell simulate original pathogen Better immune response due to simulation of natural infection Local and systemic protection Directed against different parts of the (total) virus: ‘endogenic & exogenic antigens' Mutations to original form might occur Spreading and mass application possible Often cheap per dose (compared to inactivated) Fragile to warmth and to detergents High level of MDA / Antibodies lower humeral response