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TB Notes 1, 2005

No. 1, 2005

Errors Involving Mix-Up of Tuberculin Purified Protein Derivative and Vaccine Products

The Food and Drug Administration (FDA) and CDC have identified mix-up errors between tuberculin purified protein derivative (PPD) and vaccine products reported to the FDA MedWatch Program1 and the Vaccine Adverse Event Reporting System (VAERS).2 As of September 2004, a preliminary review had identified 89 PPD/vaccine errors involving 210 adult and pediatric patients since 1990. Of these error events, 81 involved inadvertent administration of vaccine instead of tuberculin PPD, and 8 involved inadvertent administration of tuberculin PPD instead of vaccine; 67 were single case events and 22 were clusters (inadvertent administration of vaccines or tuberculin PPD products to more than one patient in the same health care facility during a 1-month period). Clusters have occurred in correctional facilities, schools and universities, public health departments, social service agencies, and occupational settings.

Vaccines commonly involved in mix-ups with the tuberculin PPD products included tetanus diphtheria toxoids, tetanus toxoid, pneumococcal polysaccharide, inactivated influenza, and hepatitis B vaccines. Most of the reported adverse events were local injection site reactions; however, three patients required hospitalization owing to systemic reactions such as “serum sickness–like illness” and asthma, although a causal relationship between the mix-up and these adverse events is not clear.  All three patients recovered.  In some error events, several patients were started on isoniazid (INH) because of false-positive TST results.  All TST results were negative when patients were retested, and INH was discontinued without any reports of adverse reactions to the medication.

Factors most commonly reported as potentially contributory to these mix-up errors included similarities in packaging (only between tetanus and diphtheria toxoids for adult use, Aventis Pasteur Inc, Swiftwater, PA, USA and Tubersol®, Aventis Pasteur Ltd, Toronto, Ontario, Canada), similar product name abbreviations (i.e., pneumococcal vaccine PPV and tuberculin PPD), pharmacy and manufacturer dispensing the wrong products, storage of vaccine and PPD products side by side in the refrigerator, use of syringe containing wrong product during simultaneous administration of vaccine and PPD products, and failure to verify the right product by two TST administrators.

Mix-up errors involving vaccines and tuberculin PPD products and measures to prevent these have been previously reported in the medical literature and health newsletters.3,4,5,6,7,8,9,10 Nonetheless, continuing reports of such errors indicate that further attention to this issue is needed to reduce the problem. Increasing awareness among health care practitioners about vaccine and PPD product confusion and providing education and training regarding TST administration may minimize or prevent these mix-up errors.

Health care practitioners should carefully read labels and record product name and lot number before each TST administration.  In addition, health care facilities should consider physical separation and product differentiation between tuberculin PPD and vaccines (e.g., PPD and vaccines can be stored in different refrigerators if feasible). FDA has issued a final rule that requires bar code labels for human and drug products and biological products, addressing medication errors associated with drugs and biologics.11  For health care facilities that possess bar code scanning technology, such scanning could help prevent errors made during pharmacy dispensing of products or during vaccine or PPD administration.

FDA and CDC are requesting reports of vaccine-PPD mix-ups, even when not resulting in an adverse event to the recipient. Reporters are encouraged to provide information about associated adverse events, potential contributory factors, and suggestions to prevent such errors.  Inadvertent administration of vaccine or PPD products may be reported to VAERS, or telephone 800-822-7967 (following vaccine administration) and FDA MedWatch Program or telephone 1-800-FDA-1088 (following PPD administration).

—Submitted by Soju Chang, MD, MPH, Kathryn O’Connell, MD, PhD, Jacquelyn Polder, BSN, MPH, M. Miles Braun, MD, MPH, Robert Ball, MD, MPH, ScM, Division of Epidemiology, Office of Biostatistics and Epidemiology, Center for Biologics Evaluation and Research, Food and Drug Administration


  3. Graham D, Dan B, Bertagnoll P, et al. Cutaneous inflammation caused by inadvertent intradermal administration of DTP instead of PPD. Am J Public Health 1981;71:1040–3.
  4. Food and Drug Administration. Mix up between Td and PPD.
  5. Hazard Alert! Confusion between tetanus diphtheria toxoid (Td) and tuberculin purified protein derivative (PPD) led to unnecessary treatment. ISMP Medication Safety Alert. May 1, 2003.
  6. Mix up Between TD and PPD. FDA Patient Safety News: Show #17, July 2003.
  7. USP Patient Safety CAPSLinkTM. October 2003.
  8. Notice to Readers: Inadvertent Intradermal Administration of Tetanus Toxoid-Containing Vaccines Instead of Tuberculosis Skin Tests, MMWR, July 30, 2004/53(29); 663-664.
  9. Worth Repeating…Tetanus toxoid vaccines again used for PPD ISMP Medication Safety Alert. August 12, 2004. (Available with subscription to ISMP Newsletter).
  10. Errors in Tuberculin Skin Testing Administration. The AcidFast Blast. August 2004, vol. 3, no. 4.
  11. Food and Drug Administration. FDA Issues Bar Code Regulation. February 25, 2004.


Released October 2008
Centers for Disease Control and Prevention
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