Centers for Disease Control and Prevention, National Center for Immunization and Respiratory Diseases, Division of Bacterial Diseases, Meningitis and Vaccine Preventable Diseases Branch, Atlanta, GA 30333, USA. ket2@cdc.gov
Using 2 real-time polymerase chain reaction (PCR) assays for Bordetella pertussis, 2 of 5 acellular pertussis vaccines were found to contain B. pertussis DNA. Because residual DNA in vaccines can cause environmental contamination, the administration of acellular pertussis vaccines to patients should be physically separated from the collection of patients' specimens for testing of B. pertussis DNA by real-time PCR.