title: Controlling measles using supplemental immunization activities: a mathematical model to inform optimal policy.
abstract: BACKGROUND
  The Measles & Rubella Initiative, a broad consortium of global health agencies, has provided support to measles-burdened countries, focusing on sustaining high coverage of routine immunization of children and supplementing it with a second dose opportunity for measles vaccine through supplemental immunization activities (SIAs). We estimate optimal scheduling of SIAs in countries with the highest measles burden.
  
  
  METHODS
  We develop an age-stratified dynamic compartmental model of measles transmission. We explore the frequency of SIAs in order to achieve measles control in selected countries and two Indian states with high measles burden. Specifically, we compute the maximum allowable time period between two consecutive SIAs to achieve measles control.
  
  
  RESULTS
  Our analysis indicates that a single SIA will not control measles transmission in any of the countries with high measles burden. However, regular SIAs at high coverage levels are a viable strategy to prevent measles outbreaks. The periodicity of SIAs differs between countries and even within a single country, and is determined by population demographics and existing routine immunization coverage.
  
  
  CONCLUSIONS
  Our analysis can guide country policymakers deciding on the optimal scheduling of SIA campaigns and the best combination of routine and SIA vaccination to control measles.
authors.affiliation: Department of Global Health and Population, Harvard T.H. Chan School of Public Health, Boston, MA, USA. Electronic address: verguet@hsph.harvard.edu.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Verguet
authors.affiliation: International Health Unit (USI), University of Montreal Hospital Research Centre (CR-CHUM), Montreal, Québec, Canada; Department of Health Administration, School of Public Health, University of Montreal, Montreal, Québec, Canada.
authors.forename: Mira
authors.initials: M
authors.lastname: Johri
authors.affiliation: Division of Infectious Diseases, Hospital for Sick Children, Toronto, Ontario, Canada; Department of Pediatrics, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada; Center for Global Health Research, Saint Michael's Hospital, Toronto, Ontario, Canada.
authors.forename: Shaun K
authors.initials: SK
authors.lastname: Morris
authors.affiliation: Center for Global Health Research, Saint Michael's Hospital, Toronto, Ontario, Canada.
authors.forename: Cindy L
authors.initials: CL
authors.lastname: Gauvreau
authors.affiliation: Center for Global Health Research, Saint Michael's Hospital, Toronto, Ontario, Canada; Division of Epidemiology, Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Prabhat
authors.initials: P
authors.lastname: Jha
authors.affiliation: Modelling and Economics Unit, Public Health England, London, United Kingdom; Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, United Kingdom.
authors.forename: Mark
authors.initials: M
authors.lastname: Jit
mesh_terms: D002648:Child; D002675:Child, Preschool; D004196:Disease Outbreaks / Q000517:prevention & control; D006291:Health Policy; D006801:Humans; D007114:Immunization / Q000379:methods; D017589:Immunization Programs / Q000379:methods*; D008457:Measles / Q000276:immunology / Q000517:prevention & control* / Q000635:transmission; D008962:Models, Theoretical; D012409:Rubella / Q000276:immunology / Q000517:prevention & control*
keywords: Child health; Immunization; Low- and middle-income settings; Mathematical modeling; Measles; Supplementary immunization activities