title: Immune responses to the O-specific polysaccharide antigen in children who received a killed oral cholera vaccine compared to responses following natural cholera infection in Bangladesh.
abstract: Current oral cholera vaccines induce lower levels of protective efficacy and shorter durations of protection in young children than in adults. Immunity against cholera is serogroup specific, and immune responses to Vibrio cholerae lipopolysaccharide (LPS), the antigen that mediates serogroup-specific responses, are associated with protection against disease. Despite this, responses against V. cholerae O-specific polysaccharide (OSP), a key component of the LPS responsible for specificity, have not been characterized in children. Here, we report a comparison of polysaccharide antibody responses in children from a region in Bangladesh where cholera is endemic, including infants (6 to 23 months, n = 15), young children (24 to 59 months, n = 14), and older children (5 to 15 years, n = 23) who received two doses of a killed oral cholera vaccine 14 days apart. We found that infants and young children receiving the vaccine did not mount an IgG, IgA, or IgM antibody response to V. cholerae OSP or LPS, whereas older children showed significant responses. In comparison to the vaccinees, young children with wild-type V. cholerae O1 Ogawa infection did mount significant antibody responses against OSP and LPS. We also demonstrated that OSP responses correlated with age in vaccinees, but not in cholera patients, reflecting the ability of even young children with wild-type cholera to develop OSP responses. These differences might contribute to the lower efficacy of protection rendered by vaccination than by wild-type disease in young children and suggest that efforts to improve lipopolysaccharide-specific responses might be critical for achieving optimal cholera vaccine efficacy in this younger age group.
authors.affiliation: Centre for Vaccine Sciences, International Centre for Diarrhoeal Disease Research, Bangladesh (ICDDR,B), Dhaka, Bangladesh. dleung@partners.org
authors.forename: Daniel T
authors.initials: DT
authors.lastname: Leung
authors.forename: Taher
authors.initials: T
authors.lastname: Uddin
authors.forename: Peng
authors.initials: P
authors.lastname: Xu
authors.forename: Amena
authors.initials: A
authors.lastname: Aktar
authors.forename: Russell A
authors.initials: RA
authors.lastname: Johnson
authors.forename: Mohammad Arif
authors.initials: MA
authors.lastname: Rahman
authors.forename: Mohammad Murshid
authors.initials: MM
authors.lastname: Alam
authors.forename: Meagan Kelly
authors.initials: MK
authors.lastname: Bufano
authors.forename: Grace
authors.initials: G
authors.lastname: Eckhoff
authors.forename: Ying
authors.initials: Y
authors.lastname: Wu-Freeman
authors.forename: Yanan
authors.initials: Y
authors.lastname: Yu
authors.forename: Tania
authors.initials: T
authors.lastname: Sultana
authors.forename: Farhana
authors.initials: F
authors.lastname: Khanam
authors.forename: Amit
authors.initials: A
authors.lastname: Saha
authors.forename: Fahima
authors.initials: F
authors.lastname: Chowdhury
authors.forename: Ashraf I
authors.initials: AI
authors.lastname: Khan
authors.forename: Richelle C
authors.initials: RC
authors.lastname: Charles
authors.forename: Regina C
authors.initials: RC
authors.lastname: Larocque
authors.forename: Jason B
authors.initials: JB
authors.lastname: Harris
authors.forename: Stephen B
authors.initials: SB
authors.lastname: Calderwood
authors.forename: Pavol
authors.initials: P
authors.lastname: Kovác
authors.forename: Firdausi
authors.initials: F
authors.lastname: Qadri
authors.forename: Edward T
authors.initials: ET
authors.lastname: Ryan
mesh_terms: D000293:Adolescent; D000907:Antibodies, Bacterial / Q000097:blood*; D001459:Bangladesh; D002648:Child; D002675:Child, Preschool; D002771:Cholera / Q000276:immunology*; D022121:Cholera Vaccines / Q000008:administration & dosage / Q000276:immunology*; D005260:Female; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D007223:Infant; D008297:Male; D019081:O Antigens / Q000276:immunology*; D015164:Vaccines, Inactivated / Q000008:administration & dosage / Q000276:immunology; D014734:Vibrio cholerae / Q000276:immunology*
chemical_list: D000907:Antibodies, Bacterial; D022121:Cholera Vaccines; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D019081:O Antigens; D015164:Vaccines, Inactivated