title: Age at First Rotavirus Vaccination and Risk of Intussusception in Infants: A Public Health Modeling Analysis.
abstract: The epidemiology of naturally occurring intussusception is known to increase significantly between the ages of 3 and 8 months. Post-licensure studies have reported a fivefold and twofold increase in intussusception in the first week after the first dose and second dose, respectively, of current rotavirus vaccines (RVs).
  
  
  
  We carried out a public health risk analysis to model the impact of age at first vaccination in relation to rotavirus vaccination and risk of intussusception in infants.
  
  
  
  We created a static model for a birth cohort followed until 1 year old to estimate the number of excess intussusception hospitalizations which could be caused by three different infant rotavirus vaccination schedules. A relative risk of 5.45 in the first 7 days after the first dose and 1.75 in the first 7 days after the second dose was used in the model.
  
  
  
  We estimated that the risk of intussusception would be the lowest at about 1 in 49,000 if both first and second dose RVs were given at <3 months of age followed by 1 in 41,000 if first dose RVs were given at <3 months and second dose RVs were given at 3-5 months. It would be highest at about 1 in 11,000 if infants received both doses when >3 months old.
  
  
  
  Our epidemiological example illustrates the importance of ensuring that the first two doses of RVs are administered in infants <3 months old whenever possible to minimize the risk of intussusception as an adverse event following rotavirus vaccination.
authors.affiliation: Infectious Disease Service, Department of Paediatric Medicine, KK Women's and Children's Hospital, 100 Bukit Timah Road, Singapore, 229899, Singapore. cheefu.yung@gmail.com.
authors.forename: Chee Fu
authors.initials: CF
authors.lastname: Yung
authors.affiliation: Infectious Disease Service, Department of Paediatric Medicine, KK Women's and Children's Hospital, 100 Bukit Timah Road, Singapore, 229899, Singapore.|Duke-National University of Singapore Graduate Medical School, 8 College Road, Singapore, 169857, Singapore.|Yong Loo Lin School of Medicine, National University of Singapore, 1E Kent Ridge Road, National University Health System Building (NUH), Singapore, 119228, Singapore.
authors.forename: Chia Yin
authors.initials: CY
authors.lastname: Chong
authors.affiliation: Infectious Disease Service, Department of Paediatric Medicine, KK Women's and Children's Hospital, 100 Bukit Timah Road, Singapore, 229899, Singapore.|Duke-National University of Singapore Graduate Medical School, 8 College Road, Singapore, 169857, Singapore.|Yong Loo Lin School of Medicine, National University of Singapore, 1E Kent Ridge Road, National University Health System Building (NUH), Singapore, 119228, Singapore.
authors.forename: Koh Cheng
authors.initials: KC
authors.lastname: Thoon
mesh_terms: D000367:Age Factors; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D007223:Infant; D007443:Intussusception / Q000453:epidemiology* / Q000209:etiology; D008962:Models, Theoretical; D011634:Public Health; D012306:Risk; D018570:Risk Assessment / Q000379:methods; D012400:Rotavirus Infections / Q000517:prevention & control*; D022243:Rotavirus Vaccines / Q000008:administration & dosage* / Q000009:adverse effects; D014611:Vaccination / Q000009:adverse effects / Q000379:methods
chemical_list: D022243:Rotavirus Vaccines