Faculty Collaboration Database

The risk of immune thrombocytopenic purpura after vaccination in children and adolescents. Pediatrics 2012 Feb;129(2):248-55

Date

01/11/2012

Pubmed ID

22232308

DOI

10.1542/peds.2011-1111

Scopus ID

2-s2.0-84856538613 (requires institutional sign-in at Scopus site)   99 Citations

Abstract

BACKGROUND: The risk of immune thrombocytopenic purpura (ITP) after childhood vaccines other than measles-mumps-rubella vaccine (MMR) is unknown.

METHODS: Using data from 5 managed care organizations for 2000 to 2009, we identified a cohort of 1.8 million children ages 6 weeks to 17 years. Potential ITP cases were identified by using diagnostic codes and platelet counts. All cases were verified by chart review. Incidence rate ratios were calculated comparing the risk of ITP in risk (1 to 42 days after vaccination) and control periods.

RESULTS: There were 197 chart-confirmed ITP cases out of 1.8 million children in the cohort. There was no elevated risk of ITP after any vaccine in early childhood other than MMR in the 12- to 19-month age group. There was a significantly elevated risk of ITP after hepatitis A vaccine at 7 to 17 years of age, and for varicella vaccine and tetanus-diphtheria-acellular pertussis vaccine at 11 to 17 years of age. For hepatitis A, varicella, and tetanus-diphtheria-acellular pertussis vaccines, elevated risks were based on one to two vaccine-exposed cases. Most cases were acute and mild with no long-term sequelae.

CONCLUSIONS: ITP is unlikely after early childhood vaccines other than MMR. Because of the small number of exposed cases and potential confounding, the possible association of ITP with hepatitis A, varicella, and tetanus-diphtheria-acellular pertussis vaccines in older children requires further investigation.

Author List

O'Leary ST, Glanz JM, McClure DL, Akhtar A, Daley MF, Nakasato C, Baxter R, Davis RL, Izurieta HS, Lieu TA, Ball R

Author

David L. McClure PhD Adjunct Assistant Professor in the Institute for Health and Equity department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Adolescent
Chickenpox Vaccine
Child
Child, Preschool
Cohort Studies
Diphtheria-Tetanus-acellular Pertussis Vaccines
Female
Hepatitis A Vaccines
Humans
Infant
Male
Purpura, Thrombocytopenic, Idiopathic
Retrospective Studies
Risk
United States
Vaccination