The Pediatric Infectious Disease Journal
March 2012 – Volume 31 – Issue 3  pp: 217-286,e52-e58,A11-A12
http://journals.lww.com/pidj/pages/currenttoc.aspx

Vaccine Reports
Incidence of Intussusception Among Infants in a Large Commercially Insured Population in the United States
Mona Eng, Patricia; Mast, T. Christopher; Loughlin, Jeanne; Clifford, C. Robin; Wong, Judy; Seeger, John D.
Pediatric Infectious Disease Journal. 31(3):287-291, March 2012.
doi: 10.1097/INF.0b013e31824213b1

Abstract:
Background: To estimate the incidence of intussusception among infants treated in inpatient and emergency department settings during the period preceding the US launch of second-generation rotavirus vaccines.

Methods: From a large US health insurance claims database, we sampled 100,000 infants aged 1 to 3 months at first diphtheria-tetanus-acellular pertussis vaccination between 2001 and 2005. Potential intussusception cases were identified on the basis of claims and were confirmed by medical record review. Incidence rates (IRs) and 95% confidence intervals (CIs) were estimated based on follow-up from first diphtheria-tetanus-acellular pertussis dose to up to 1 year of age, and within 21, 30, and 60 days after each dose.

Results: The IR of intussusception in the first year of life was 0.33/1000 person-years based on 22 confirmed cases (95% CI: 0.21–0.50/1000 person-years). The age-specific incidence peaked among infants aged 5 months (IR: 0.82/1000 person-years; 95% CI: 0.30–1.78/1000 person-years). During the 21, 30, and 60 days following any dose, the incidence per 1000 person-years was 0.27, 0.24, and 0.33, respectively.

Conclusion: The rates described in this study can serve as a benchmark for comparison with incidences observed after the introduction of the second-generation rotavirus vaccines.

Postmarketing Evaluation of the Short-term Safety of the Pentavalent Rotavirus Vaccine
Loughlin, Jeanne; Mast, T. Christopher; Doherty, Michael C.; Wang, Florence T.; Wong, Judy; Seeger, John D.
Pediatric Infectious Disease Journal. 31(3):292-296, March 2012.
doi: 10.1097/INF.0b013e3182421390

Abstract:
Background: A pentavalent rotavirus vaccine (RV5) demonstrated efficacy and safety in a large clinical trial before US licensure in 2006. The primary objective of this observational study was to assess the occurrence of intussusception (IS) among infants who received RV5 in routine use. Secondary objectives assessed the occurrence of Kawasaki disease (KD) and general safety.

Methods: We identified and followed infants with a health insurance claim for RV5 during the first 2 years of RV5 availability. Concurrent and historical cohorts receiving diphtheria-tetanus-acellular pertussis (DTaP) vaccine were used as comparators; the historical DTaP cohort informed sequential monitoring boundaries for IS and KD. Medical records from potential IS and KD cases were reviewed to confirm outcomes. General safety was evaluated across a wide range of outcomes using prespecified criteria. Incidence rates for outcomes along with relative risks and 95% confidence intervals (CIs) were estimated.

Results: The 85,397 RV5 and 62,820 DTaP recipients contributed 17,433 and 12,339 person-years, resulting in 6 and 5 confirmed cases of IS, respectively, within 30 days following any dose. The relative risk of IS was 0.8 (95% confidence interval: 0.22–3.52). The number of IS or KD cases did not cross the monitoring boundaries. The general safety evaluation did not identify any specific diagnoses or patterns of diagnoses that might suggest other safety concerns.

Conclusion: RV5 was not associated with an increased risk of IS, KD, or any other recognized health outcome.