In Africa and Asia these vaccines reduced severe disease among infants and countries that have put in place national immunization programs have seen a decline in the rates and severity of disease.
在非洲和亚洲，这些疫苗的使用已经大大减少了婴儿 患重病的几率，而且那些推行了国家免疫计划的国家在疾病发生率和严重程度上已经有了明显下降。