Modelling the spatio-temporal risk of measles outbreaks and options for their control in Kenya

The measles control programme in Kenya is considered to be at it end phase. There has been long-term high level coverage of measles containing vaccine (MCV) at 9m reaching around 90% in 2010-12. Supplementary immunization activities (SIAs) are undertaken periodically (last done in 2016) to reduce the build-up of susceptibles in the age range 9m to 14 years. However, sporadic outbreaks continue, and data suggests vaccine uptake of MCV dose 1 has decreased over the last 5 years (WHO & UNICEF 2017, Manakongtreecheep & Davis 2017). A second dose of MCV was introduced in 2013 at 18months of age, but coverage is only at around 35%, and there is little confidence that this can easily be improved. There is national case-based surveillance, with follow up, through IgM serology from cases of rash illness. This study seeks to understand the possible reasons for continued outbreaks and to predict the implications of various vaccine strategies by modelling the Spatio-temporal risk of measles outbreaks and options for their control in Kenya.