Immunization coverage and timing varied widely by country, as did the proportion of children immunized and with what vaccines. The mean age at first immunization was 1.1 months.

• 在各个国家中，免疫反应范围和时效变化很大。无论是用何种疫苗，获得免疫性的儿童所占比率变化同样很大。获得出示免疫力的儿童的平均年龄是1.；1月。