title: Immune Responses to an Oral Cholera Vaccine in Internally Displaced Persons in South Sudan.
abstract: Despite recent large-scale cholera outbreaks, little is known about the immunogenicity of oral cholera vaccines (OCV) in African populations, particularly among those at highest cholera risk. During a 2015 preemptive OCV campaign among internally displaced persons in South Sudan, a year after a large cholera outbreak, we enrolled 37 young children (1-5 years old), 67 older children (6-17 years old) and 101 adults (≥18 years old), who received two doses of OCV (Shanchol) spaced approximately 3 weeks apart. Cholera-specific antibody responses were determined at days 0, 21 and 35 post-immunization. High baseline vibriocidal titers (>80) were observed in 21% of the participants, suggesting recent cholera exposure or vaccination. Among those with titers ≤80, 90% young children, 73% older children and 72% adults seroconverted (≥4 fold titer rise) after the 1stOCV dose; with no additional seroconversion after the 2nddose. Post-vaccination immunological endpoints did not differ across age groups. Our results indicate Shanchol was immunogenic in this vulnerable population and that a single dose alone may be sufficient to achieve similar short-term immunological responses to the currently licensed two-dose regimen. While we found no evidence of differential response by age, further immunologic and epidemiologic studies are needed.
authors: Division of Infectious Diseases, Department of Internal Medicine, University of Utah School of Medicine, Salt Lake City, Utah, USA.
authors: Anita S
authors: AS
authors: Iyer
authors: World Health Organization, Juba, South Sudan.
authors: Malika
authors: M
authors: Bouhenia
authors: Republic of South Sudan Ministry of Health, Juba, South Sudan.
authors: John
authors: J
authors: Rumunu
authors: World Health Organization, Juba, South Sudan.
authors: Abdinasir
authors: A
authors: Abubakar
authors: Division of Infectious Diseases, Department of Internal Medicine, University of Utah School of Medicine, Salt Lake City, Utah, USA.
authors: Randon J
authors: RJ
authors: Gruninger
authors: World Health Organization, Juba, South Sudan.
authors: Jane
authors: J
authors: Pita
authors: Republic of South Sudan Ministry of Health, Juba, South Sudan.
authors: Richard Lako
authors: RL
authors: Lino
authors: Republic of South Sudan Ministry of Health, Juba, South Sudan.
authors: Lul L
authors: LL
authors: Deng
authors: World Health Organization, Juba, South Sudan.
authors: Joseph F
authors: JF
authors: Wamala
authors: Division of Infectious Diseases, Massachusetts General Hospital, Boston, MA, USA.
authors: Edward T
authors: ET
authors: Ryan
authors: World Health Organization, Geneva, Switzerland.
authors: Stephen
authors: S
authors: Martin
authors: World Health Organization, Geneva, Switzerland.
authors: Dominique
authors: D
authors: Legros
authors: Department of Epidemiology, Johns Hopkins University, Baltimore, MD, USA.
authors: Justin
authors: J
authors: Lessler
authors: Department of International Health, Johns Hopkins University, Baltimore, MD, USA.
authors: David A
authors: DA
authors: Sack
authors: Department of International Health, Johns Hopkins University, Baltimore, MD, USA.|Epicentre, Paris, France.
authors: Francisco J
authors: FJ
authors: Luquero
authors: Division of Infectious Diseases, Department of Internal Medicine, University of Utah School of Medicine, Salt Lake City, Utah, USA.|Division of Microbiology and Immunology, Department of Pathology, University of Utah School of Medicine, Salt Lake City, Utah, USA.
authors: Daniel T
authors: DT
authors: Leung
authors: Department of Epidemiology, Johns Hopkins University, Baltimore, MD, USA.
authors: Andrew S
authors: AS
authors: Azman
mesh_terms: D000284:Administration, Oral; D000293:Adolescent; D000907:Antibodies, Bacterial / Q000276:immunology; D000917:Antibody Formation / Q000276:immunology*; D002648:Child; D002675:Child, Preschool; D002771:Cholera / Q000453:epidemiology / Q000276:immunology*; D022121:Cholera Vaccines / Q000276:immunology*; D004196:Disease Outbreaks / Q000517:prevention & control; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D000068037:South Sudan / Q000453:epidemiology; D014611:Vaccination / Q000379:methods; D015164:Vaccines, Inactivated / Q000276:immunology; D014734:Vibrio cholerae / Q000276:immunology
chemical_list: D000907:Antibodies, Bacterial; D022121:Cholera Vaccines; D015164:Vaccines, Inactivated; C000588783:shanchol