title: Effectiveness of monovalent rotavirus vaccine in a high-income, predominant-use setting.
abstract: OBJECTIVE
  We assessed monovalent rotavirus (RV1) vaccine effectiveness (VE) in a high-income setting with RV1 predominant use, and examined the burden of pediatric rotavirus gastroenteritis following the implementation of an RV1-only vaccination program.
  
  
  METHODS
  We conducted active rotavirus gastroenteritis surveillance among children 8 weeks to <3 years of age at three hospitals. Participant information and vaccination histories were collected via parent/guardian interview and medical records. Stool specimens were tested for rotavirus; positive specimens were genotyped. The effect of increasing RV1 coverage on rotavirus prevalence was examined as a weekly time series via binomial regression with a log link function, using either categorical season or mean 2-dose rotavirus seasonal vaccine coverage as the exposure variable. As compared with RV1 vaccine formulation, rotavirus genotypes were classified as homotypic, partly-heterotypic, or heterotypic; prevalence of each was compared by season. A test-negative case-control design was used to examine RV1 VE against hospitalization or emergency visits.
  
  
  RESULTS
  We enrolled 866 participants in active surveillance; of these, 384 (44.3%) were eligible for VE analyses. After adjustment for season, we detected a 70.1% (95% CI: 21.9%, 88.6%) relative decrease in rotavirus prevalence in the 2013-14 season compared with 2012-13 season. On average, a 1% increase in ≥2-dose rotavirus coverage among children 1 year of age was associated with a 3.8% (95% CI: 1.8%, 5.8%) relative decrease in rotavirus prevalence. Rotavirus homotypic strain prevalence decreased, with 77% (95% CI: 68%, 89%) versus 8% (95% CI: 0%, 36%) prevalence during the 2011-12 and 2013-14 seasons, respectively. Adjusted 2-dose RV1 VE was 91.2% (95% CI: 61.6%, 98.0%).
  
  
  CONCLUSIONS
  RV1 vaccine was highly effective to prevent rotavirus hospitalizations and emergency visits among children <3 years of age in a high-income setting with its predominant use. Our estimates were similar to high-income settings with concurrent RV1 and pentavalent vaccine use.
authors.affiliation: McGill University, Montreal, QC, Canada.
authors.forename: Margaret K
authors.initials: MK
authors.lastname: Doll
authors.affiliation: McGill University, Montreal, QC, Canada.
authors.forename: David L
authors.initials: DL
authors.lastname: Buckeridge
authors.affiliation: McGill University, Montreal, QC, Canada.
authors.forename: Kathryn T
authors.initials: KT
authors.lastname: Morrison
authors.affiliation: Centre Hospitalier Universitaire de Sherbrooke, Sherbrooke, QC, Canada.
authors.forename: Arnaud
authors.initials: A
authors.lastname: Gagneur
authors.affiliation: Sainte-Justine University Hospital, Montreal, QC, Canada.
authors.forename: Bruce
authors.initials: B
authors.lastname: Tapiero
authors.affiliation: Laboratoire de santé publique du Quebec (LSPQ), Sainte-Anne-de-Bellevue, Montreal, QC, Canada.
authors.forename: Hugues
authors.initials: H
authors.lastname: Charest
authors.affiliation: McGill University, Montreal, QC, Canada; The Montreal Children's Hospital, Montreal, QC, Canada. Electronic address: caroline.quach@mcgill.ca.
authors.forename: Caroline
authors.initials: C
authors.lastname: Quach
mesh_terms: D002675:Child, Preschool; D019049:Developed Countries; D004632:Emergency Medical Services; D062665:Epidemiological Monitoring; D005243:Feces / Q000821:virology; D005260:Female; D005759:Gastroenteritis / Q000453:epidemiology* / Q000517:prevention & control*; D005838:Genotype; D006760:Hospitalization; D006801:Humans; D007223:Infant; D008297:Male; D015995:Prevalence; D011446:Prospective Studies; D012401:Rotavirus / Q000145:classification / Q000302:isolation & purification; D012400:Rotavirus Infections / Q000453:epidemiology* / Q000517:prevention & control*; D022243:Rotavirus Vaccines / Q000008:administration & dosage* / Q000276:immunology*; D016896:Treatment Outcome; D014613:Vaccines, Attenuated / Q000008:administration & dosage / Q000276:immunology
chemical_list: C492457:RIX4414 vaccine; D022243:Rotavirus Vaccines; D014613:Vaccines, Attenuated
keywords: Effectiveness; Rotavirus; Vaccination