Thrombocytopenia after vaccination: case reports to the US Vaccine Adverse Event Reporting System, 1990-2008.
Vaccine. 2010 Nov 29. Epub 2010 Nov 29. PMID: 21126606
Food and Drug Administration HFM-222, FDA/CBER/OBE, 1401 Rockville Pike, Rockville, MD 20852, United States.
We reviewed thrombocytopenia (TP) reports to the US Vaccine Adverse Event Reporting System (VAERS). We examined TP patterns for differences in single versus multiple immunization reports, presence of a live viral vaccine, seriousness, age, and interval to symptom onset. We found 1510 reports of possible TP and after exclusions evaluated 1440 for possible causes. Most (1078; 75%) met the regulatory definition of a serious adverse event. TP was reported after inactivated and live viral vaccines. Platelet counts<10×10(9)/L were reported. Identified vaccines could be prioritized for hypothesis-testing studies.