title: Natural cholera infection-derived immunity in an endemic setting.
abstract: BACKGROUND
  Live oral cholera vaccines may protect against cholera in a manner similar to natural cholera infections. However, information on which to base these vaccines is limited.
  
  
  METHODS
  The study was conducted in a cholera-endemic population in Bangladesh. Patients with cholera (index patients) detected between 1991 and 2000 were age-matched to 4 cholera-free controls and then followed up during the subsequent 3 years.
  
  
  RESULTS
  El Tor cholera was associated with a 65% (95% confidence interval [CI], 37%-81%; P < .001) lower risk of a subsequent El Tor episode. Reduction of the risk of subsequent El Tor cholera was similar for children < 5 years and for older persons and was sustained during all 3 years of follow-up. Having El Tor Inaba cholera was associated with lower risks of both El Tor Inaba and El Tor Ogawa cholera, but having El Tor Ogawa cholera was associated only with a reduced risk of El Tor Ogawa cholera. O139 cholera was associated with a 63% (95% CI, -61% to 92%; P = .18) lower risk of subsequent O139 cholera, but there was no evidence of cross-protection between the O1 and O139 serogroups.
  
  
  CONCLUSIONS
  Live oral cholera vaccines designed to protect against the O1 and O139 serogroups should contain at least the Inaba serotype and strains of both serogroups.
authors.affiliation: International Vaccine Institute, Seoul, Republic of Korea. mali@ivi.int
authors.forename: Mohammad
authors.initials: M
authors.lastname: Ali
authors.forename: Michael
authors.initials: M
authors.lastname: Emch
authors.forename: Jin Kyung
authors.initials: JK
authors.lastname: Park
authors.forename: Mohammad
authors.initials: M
authors.lastname: Yunus
authors.forename: John
authors.initials: J
authors.lastname: Clemens
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001459:Bangladesh / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D002771:Cholera / Q000453:epidemiology* / Q000276:immunology*; D022121:Cholera Vaccines / Q000276:immunology; D019353:Endemic Diseases; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D012703:Serotyping; D014734:Vibrio cholerae / Q000145:classification / Q000276:immunology*; D055815:Young Adult
chemical_list: D022121:Cholera Vaccines