Methods According to the unified investigation scheme,a persepective investigation on vaccination reaction of the two type DPT(old and new type)was carried out.

• 方法在西安市碑林、新城、莲湖区,按统一调查方案,对新DPT和百白破混合制剂(老DPT)免疫接种反应进行前瞻性调查。