title: Single-dose Live Oral Cholera Vaccine CVD 103-HgR Protects Against Human Experimental Infection With Vibrio cholerae O1 El Tor.
abstract: No licensed cholera vaccine is presently available in the United States. Cholera vaccines available in other countries require 2 spaced doses. A single-dose cholera vaccine that can rapidly protect short-notice travelers to high-risk areas and help control explosive outbreaks where logistics render 2-dose immunization regimens impractical would be a major advance.PXVX0200, based on live attenuated Vibrio cholerae O1 classical Inaba vaccine strain CVD 103-HgR, elicits seroconversion of vibriocidal antibodies (a correlate of protection) within 10 days of a single oral dose. We investigated the protection conferred by this vaccine in a human cholera challenge model.
  
  
  
  Consenting healthy adult volunteers, 18-45 years old, were randomly allocated 1:1 to receive 1 oral dose of vaccine (approximately 5 × 10(8) colony-forming units [CFU]) or placebo in double-blind fashion. Volunteers ingested approximately 1 × 10(5) CFU of wild-type V. cholerae O1 El Tor Inaba strain N16961 10 days or 3 months after vaccination and were observed on an inpatient research ward for stool output measurement and management of hydration.
  
  
  
  The vaccine was well tolerated, with no difference in adverse event frequency among 95 vaccinees vs 102 placebo recipients. The primary endpoint, moderate (≥3.0 L) to severe (≥5.0 L) diarrheal purge, occurred in 39 of 66 (59.1%) placebo controls but only 2 of 35 (5.7%) vaccinees at 10 days (vaccine efficacy, 90.3%; P < .0001) and 4 of 33 (12.1%) vaccinees at 3 months (vaccine efficacy, 79.5%; P < .0001).
  
  
  
  The significant vaccine efficacy documented 10 days and 3 months after 1 oral dose of PXVX0200 supports further development as a single-dose cholera vaccine.
  
  
  
  NCT01895855.
authors.affiliation: Center for Vaccine Development, University of Maryland School of Medicine, Baltimore.
authors.forename: Wilbur H
authors.initials: WH
authors.lastname: Chen
authors.affiliation: Cincinnati Children's Hospital Medical Center, Ohio.
authors.forename: Mitchell B
authors.initials: MB
authors.lastname: Cohen
authors.affiliation: Vaccine Testing Center, University of Vermont College of Medicine, Burlington.
authors.forename: Beth D
authors.initials: BD
authors.lastname: Kirkpatrick
authors.affiliation: Cincinnati Children's Hospital Medical Center, Ohio.
authors.forename: Rebecca C
authors.initials: RC
authors.lastname: Brady
authors.affiliation: Cincinnati Children's Hospital Medical Center, Ohio.
authors.forename: David
authors.initials: D
authors.lastname: Galloway
authors.affiliation: PaxVax, Inc, Menlo Park, California.
authors.forename: Marc
authors.initials: M
authors.lastname: Gurwith
authors.affiliation: National Institute of Allergy and Infectious Diseases, Bethesda, Maryland.
authors.forename: Robert H
authors.initials: RH
authors.lastname: Hall
authors.affiliation: Center for Vaccine Development, University of Maryland School of Medicine, Baltimore.
authors.forename: Robert A
authors.initials: RA
authors.lastname: Kessler
authors.affiliation: PaxVax, Inc, Menlo Park, California.
authors.forename: Michael
authors.initials: M
authors.lastname: Lock
authors.affiliation: PaxVax, Inc, Menlo Park, California.
authors.forename: Douglas
authors.initials: D
authors.lastname: Haney
authors.affiliation: Vaccine Testing Center, University of Vermont College of Medicine, Burlington.
authors.forename: Caroline E
authors.initials: CE
authors.lastname: Lyon
authors.affiliation: Center for Vaccine Development, University of Maryland School of Medicine, Baltimore.
authors.forename: Marcela F
authors.initials: MF
authors.lastname: Pasetti
authors.affiliation: PaxVax, Inc, Menlo Park, California.
authors.forename: Jakub K
authors.initials: JK
authors.lastname: Simon
authors.affiliation: Cincinnati Children's Hospital Medical Center, Ohio.
authors.forename: Flora
authors.initials: F
authors.lastname: Szabo
authors.affiliation: Center for Vaccine Development, University of Maryland School of Medicine, Baltimore.
authors.forename: Sharon
authors.initials: S
authors.lastname: Tennant
authors.affiliation: Center for Vaccine Development, University of Maryland School of Medicine, Baltimore.
authors.forename: Myron M
authors.initials: MM
authors.lastname: Levine
mesh_terms: D000293:Adolescent; D000328:Adult; D000907:Antibodies, Bacterial / Q000097:blood* / Q000276:immunology; D002771:Cholera / Q000276:immunology / Q000517:prevention & control*; D022121:Cholera Vaccines / Q000008:administration & dosage* / Q000009:adverse effects / Q000276:immunology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D041241:Vibrio cholerae O1 / Q000276:immunology*; D055815:Young Adult
chemical_list: D000907:Antibodies, Bacterial; D022121:Cholera Vaccines; C414990:cholera vaccine CVD 103-HgR
keywords: challenge; cholera; efficacy; vaccine; volunteer