计划免疫中的卡介苗、脊髓灰质炎疫苗、百白破三联苗和麻疹疫苗（以下简称四苗）的预算供应，基层一般参照历年常规用量，上级防疫部门则主要根据各地人口资料、发病情况和一定的疫苗损耗系数调整分配。近年来，由于农村计划生育工作的落实，人口出生率显著下降，疫苗使用率也 Planned immunization BCG, poliomyelitis vaccine, diphtheria triple vaccine and measles vaccine (hereinafter referred to as four vaccine) budgetary provision, the grass-roots general reference to the conventional use of the calendar year, the superior epidemic prevention departments are mainly based on population information around the incidence and certain Vaccine Loss Coefficient Adjustment Assignment. In recent years, due to the implementation of rural family planning, the birth rate dropped significantly, and the vaccine utilization rate