The NCDC said majority of the cases were among people who had not been vaccinated, even though diphtheria is covered by Nigeria's routine childhood immunization program.

尼日利亚疾控中心表示，大多数病例发生在没有接种疫苗的人群中，尽管尼日利亚的常规儿童免疫计划涵盖了白喉。