title: Efficacy, safety and immunogenicity of a human rotavirus vaccine (RIX4414) in Hong Kong children up to three years of age: a randomized, controlled trial.
abstract: BACKGROUND
  A phase III, double-blind, randomized, controlled trial was conducted in Hong Kong to evaluate the efficacy, safety and immunogenicity of a human rotavirus vaccine, RIX4414 (Rotarix) against severe rotavirus gastroenteritis in children up to three years of age.
  
  
  METHODS
  Healthy infants aged 6-12 weeks were enrolled between 08-December-2003 and 31-August-2005 and received two oral doses of either RIX4414 vaccine (N=1513) or placebo (N=1512) given 2 months apart. Vaccine efficacy was assessed from two weeks post-Dose 2 until the children were two and three years of age. Anti-rotavirus IgA seroconversion rate was calculated pre-vaccination and 1-2 months post-Dose 2 using ELISA (cut-off=20 U/mL) for 100 infants. Safety was assessed until the children were two years of age; serious adverse events (SAEs) were recorded throughout the study period.
  
  
  RESULTS
  In children aged two and three years of life, vaccine efficacy against severe rotavirus gastroenteritis was 95.6% (95% CI: 73.1%-99.9%) and 96.1% (95% CI: 76.5%-99.9%), respectively. The seroconversion rate 1-2 months after the second dose of RIX4414 was 97.5% (95% CI: 86.8%-99.9%). At least one SAE was recorded in 439 and 477 infants who were administered RIX4414 and placebo, respectively (p-value=0.130). Six intussusception cases were reported (RIX4414=4; placebo=2) and none was assessed to be vaccine-related.
  
  
  CONCLUSIONS
  RIX4414 was efficacious, immunogenic and safe in the prevention of rotavirus gastroenteritis for at least two years post-vaccination in Hong Kong children.
authors.affiliation: Department of Paediatrics and Adolescent Medicine, The University of Hong Kong, Hong Kong. lauylung@hku.hk.
authors.forename: Yu-Lung
authors.initials: YL
authors.lastname: Lau
authors.forename: E Anthony S
authors.initials: EA
authors.lastname: Nelson
authors.forename: Kin-Hung
authors.initials: KH
authors.lastname: Poon
authors.forename: Paul K S
authors.initials: PK
authors.lastname: Chan
authors.forename: Susan
authors.initials: S
authors.lastname: Chiu
authors.forename: Rita
authors.initials: R
authors.lastname: Sung
authors.forename: Chi Wai
authors.initials: CW
authors.lastname: Leung
authors.forename: Daniel
authors.initials: D
authors.lastname: Ng
authors.forename: Yee Man
authors.initials: YM
authors.lastname: Ma
authors.forename: Desmond
authors.initials: D
authors.lastname: Chan
authors.forename: Tsz Leung
authors.initials: TL
authors.lastname: Lee
authors.forename: Joyce
authors.initials: J
authors.lastname: Tang
authors.forename: Yat Wah
authors.initials: YW
authors.lastname: Kwan
authors.forename: Patricia
authors.initials: P
authors.lastname: Ip
authors.forename: Marco
authors.initials: M
authors.lastname: Ho
authors.forename: Lai-Wah Eva
authors.initials: LW
authors.lastname: Fung
authors.forename: Haiwen
authors.initials: H
authors.lastname: Tang
authors.forename: P V
authors.initials: PV
authors.lastname: Suryakiran
authors.forename: Htay Htay
authors.initials: HH
authors.lastname: Han
authors.forename: Hans
authors.initials: H
authors.lastname: Bock
mesh_terms: D000284:Administration, Oral; D000914:Antibodies, Viral / Q000097:blood / Q000276:immunology; D002675:Child, Preschool; D004311:Double-Blind Method; D005759:Gastroenteritis / Q000276:immunology / Q000517:prevention & control* / Q000821:virology; D006723:Hong Kong; D006801:Humans; D007115:Immunization Schedule; D007070:Immunoglobulin A / Q000097:blood / Q000276:immunology; D007223:Infant; D007443:Intussusception / Q000139:chemically induced; D012401:Rotavirus; D012400:Rotavirus Infections / Q000276:immunology / Q000517:prevention & control*; D022243:Rotavirus Vaccines / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*
chemical_list: D000914:Antibodies, Viral; D007070:Immunoglobulin A; D022243:Rotavirus Vaccines