title: Comparative effectiveness of different strategies of oral cholera vaccination in bangladesh: a modeling study.
abstract: BACKGROUND
  Killed, oral cholera vaccines have proven safe and effective, and several large-scale mass cholera vaccination efforts have demonstrated the feasibility of widespread deployment. This study uses a mathematical model of cholera transmission in Bangladesh to examine the effectiveness of potential vaccination strategies.
  
  
  RESULTS
  We developed an age-structured mathematical model of cholera transmission and calibrated it to reproduce the dynamics of cholera in Matlab, Bangladesh. We used the model to predict the effectiveness of different cholera vaccination strategies over a period of 20 years. We explored vaccination programs that targeted one of three increasingly focused age groups (the entire vaccine-eligible population of age one year and older, children of ages 1 to 14 years, or preschoolers of ages 1 to 4 years) and that could occur either as campaigns recurring every five years or as continuous ongoing vaccination efforts. Our modeling results suggest that vaccinating 70% of the population would avert 90% of cholera cases in the first year but that campaign and continuous vaccination strategies differ in effectiveness over 20 years. Maintaining 70% coverage of the population would be sufficient to prevent sustained transmission of endemic cholera in Matlab, while vaccinating periodically every five years is less effective. Selectively vaccinating children 1-14 years old would prevent the most cholera cases per vaccine administered in both campaign and continuous strategies.
  
  
  CONCLUSIONS
  We conclude that continuous mass vaccination would be more effective against endemic cholera than periodic campaigns. Vaccinating children averts more cases per dose than vaccinating all age groups, although vaccinating only children is unlikely to control endemic cholera in Bangladesh. Careful consideration must be made before generalizing these results to other regions.
authors.affiliation: Center for Statistics and Quantitative Infectious Diseases; Vaccine and Infectious Disease Division; Fred Hutchinson Cancer Research Center; Seattle, Washington, United States of America.
authors.forename: Dobromir T
authors.initials: DT
authors.lastname: Dimitrov
authors.affiliation: Center for Statistics and Quantitative Infectious Diseases; Vaccine and Infectious Disease Division; Fred Hutchinson Cancer Research Center; Seattle, Washington, United States of America.
authors.forename: Christopher
authors.initials: C
authors.lastname: Troeger
authors.affiliation: Center for Statistics and Quantitative Infectious Diseases; Vaccine and Infectious Disease Division; Fred Hutchinson Cancer Research Center; Seattle, Washington, United States of America; Department of Biostatistics; University of Washington; Seattle, Washington, United States of America.
authors.forename: M Elizabeth
authors.initials: ME
authors.lastname: Halloran
authors.affiliation: Department of Biostatistics; University of Florida; Gainesville, Florida, United States of America.
authors.forename: Ira M
authors.initials: IM
authors.lastname: Longini
authors.affiliation: Center for Statistics and Quantitative Infectious Diseases; Vaccine and Infectious Disease Division; Fred Hutchinson Cancer Research Center; Seattle, Washington, United States of America.
authors.forename: Dennis L
authors.initials: DL
authors.lastname: Chao
mesh_terms: D000284:Administration, Oral; D000293:Adolescent; D001459:Bangladesh / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D002771:Cholera / Q000453:epidemiology / Q000517:prevention & control* / Q000635:transmission; D022121:Cholera Vaccines / Q000276:immunology*; D003362:Cost-Benefit Analysis; D006801:Humans; D007223:Infant; D008297:Male; D032541:Mass Vaccination; D008962:Models, Theoretical; D008969:Molecular Sequence Data
chemical_list: D022121:Cholera Vaccines