About 15% of people infected with yellow feverprogress to a severe form of the illness, and up to half of those will die, as there is no cure for yellow fever.
15022
而治疗仅能缓解病人的不适感。
The treatment is aimed simply at reducing patients’ discomfort.
15023
绝大多数报告病例和死亡病例发生在撒哈拉以南非洲。
The vast majority of reported cases and deaths occur in sub-Saharan Africa.
15024
在非洲流行地区，随着年龄增加，人们自然获得黄热病免疫力，因此儿童感染风险最高。
In endemic regions of Africa, yellow fever natural immunity is acquired with age, putting children at highest risk of infection.
Over the past two decades, the number of yellow fever cases worldwide has increased due to declining population immunity to infection, deforestation, urbanization, population movements and climate change.
15026
接种疫苗是最有效的预防措施
Vaccination is the most effective measure
15027
接种疫苗被认为是最重要和最有效的黄热病预防措施。
Vaccination is considered to be the most important and effective measure against yellow fever.
15028
99%的人在接种疫苗后30日内获得免疫保护。
Protective immunity develops within 30 days for 99% of people receiving the vaccination.
15029
44个黄热病流行国中，31个位于非洲。
For routine immunization programmes in Africa, home to 31 of the 44 yellow-fever endemic countries, the vaccine costs about $0.82 per dose.