title: Transmissibility, infectivity and immunogenicity of a live human parainfluenza type 3 virus vaccine (HPIV3cp45) among susceptible infants and toddlers.
abstract: BACKGROUND
  This study examined the transmissibility between young children of an intranasally administered live attenuated human parainfluenza virus type 3 (HPIV3)-cp45 vaccine candidate.
  
  
  METHODS
  Eighty subjects were enrolled in playgroups among whom there was at least one infected vaccinee in close contact with a seronegative placebo recipient over 21 days without a confounding infection with wtHPIV3. Following vaccination viral cultures were obtained on nine occasions to detect shedding and transmission of HPIV3cp45. Serum antibody titers were measured before and 7 weeks after vaccination.
  
  
  RESULTS
  No child fulfilled the criteria for transmission of HPIV3cp45 giving a risk of transmission of 0.04 (95% CI 0.01-0.19), hence establishing that HPIV3cp45 is less infectious than wtHPIV3 and risk of transmission is not a limitation to further clinical development of this vaccine candidate.
authors.affiliation: University of the Witwatersrand/Medical Research Council Respiratory and Meningeal Pathogens Research Unit, South Africa. madhis@hivsa.com
authors.forename: Shabir A
authors.initials: SA
authors.lastname: Madhi
authors.forename: Clare
authors.initials: C
authors.lastname: Cutland
authors.forename: Yuwei
authors.initials: Y
authors.lastname: Zhu
authors.forename: Jill G
authors.initials: JG
authors.lastname: Hackell
authors.forename: Frances
authors.initials: F
authors.lastname: Newman
authors.forename: Nigel
authors.initials: N
authors.lastname: Blackburn
authors.forename: Brian R
authors.initials: BR
authors.lastname: Murphy
authors.forename: Robert B
authors.initials: RB
authors.lastname: Belshe
authors.forename: Ruth A
authors.initials: RA
authors.lastname: Karron
authors.forename: Anne M
authors.initials: AM
authors.lastname: Deatly
authors.forename: William C
authors.initials: WC
authors.lastname: Gruber
authors.forename: David I
authors.initials: DI
authors.lastname: Bernstein
authors.forename: Peter F
authors.initials: PF
authors.lastname: Wright
mesh_terms: D000914:Antibodies, Viral / Q000097:blood; D002675:Child, Preschool; D004311:Double-Blind Method; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007223:Infant; D010224:Parainfluenza Virus 3, Human / Q000276:immunology* / Q000472:pathogenicity; D010253:Respirovirus Infections / Q000635:transmission*; D014611:Vaccination; D014613:Vaccines, Attenuated / Q000276:immunology; D014765:Viral Vaccines / Q000276:immunology*
chemical_list: D000914:Antibodies, Viral; D014613:Vaccines, Attenuated; D014765:Viral Vaccines