The programme of measles elimination in the WHO African region: current state of the problem

Abstract

In the WHO African region (AFR), measles is characterized by severe complications with a high risk of death due to malnutrition, vitamin А deficiency, concomitant infections. Measles viruses of genotype B (B1, B2, B3) are the endemic viruses in the African region (47 countries). The strategy for the elimination of measles in AFR was based on the combination of supplementary immunization programmes (SIAs) for children under 14 years of age and routine vaccination of at least 90% of children 9-15 months of age. It was recommended to repeat the SIAs every 3-5 years. The number of measles cases decreased by 83-97% during the first year due to the strategy. The recommended age of routine vaccination in AFR is 9 months — this is a way to reduce measles-caused infant mortality. However, the level of seroconversion is not sufficient (85%). To eliminate measles completely by 2020, it’s recommended the use of two-dose regimens — vaccination and revaccination. Vaccination coverage with a single dose of measles vaccine in the African region increased to 74% in 2015, but the high incidence of measles in the region persists. In 2013-2016 there are 103,161 cases of measles among children under 6 years of age in AFR ; 79% of which were not vaccinated (or had unknown vaccination status). In 2013, the measles vaccine program in several AFR countries was disrupted by the epidemic of Ebola. In countries where the epidemic has ended, the vaccination was recommended to be resumed for persons who may have missed routine immunization. There are problems in the implementation of measles elimination in AFR: insufficient equipment of medical centers and lack of qualified personnel, poor population awareness, poorly developed communication system, military conflicts.