Adacel (Tdap) and Daptacel (DTaP) confusion

We’re aware of several mix-ups between DAPTACEL (diphtheria and tetanus toxoids and acellular pertussis vaccine adsorbed) and ADACEL (tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis vaccine adsorbed). Daptacel is for active immunization in infants and children 6 weeks to 6 years old. Adacel is indicated for active booster immunization as a single dose in persons 11 to 64 years old and is the first vaccine approved as a pertussis booster for adults. The component antigens in Adacel and Daptacel are the same, but the relative amounts are much greater with the infant vaccination. As such, these are easy to confuse.

In one clinic, 13 adults were vaccinated with Daptacel in error. At another clinic, seven adults received Daptacel instead of Adacel. Fortunately, none of the patients appeared to have experienced any unusual vaccine reactions despite the fact that the pediatric formulation contains greater amounts of the detoxified pertussis toxin and diphtheria toxoid. The similarities of the brand names, generic designations, and vaccine abbreviations (Tdap and DTaP) were felt to have contributed to the confusion. Packaging similarities also contribute to errors. We’ve previously described how the unusual color schemes and highly stylized labeling of sanofi pasteur (Aventis Pasteur) vaccines contribute to confusion (see photos).  

To prevent mix-ups between these two products, please share this article with your professional colleagues. Separate stock of the pediatric and adult formulations, and place alerts on the products (e.g., “Adult” or “Pediatric”). Where feasible, also place alerts in computer software to warn practitioners about the differences between the adult and pediatric formulations. If possible, configure the order entry system to disallow selection of the wrong product based on the patient’s age. Verify patient age prior to dispensing or administering any vaccines. Also, check your computer system to see how the vaccine names are displayed. Reporters have told us that commonly used drug references, drug information vendor databases, and drug wholesalers reference the component antigens of Adacel as diphtheria, tetanus, and acellular pertussis rather than the way it’s listed on the package label, with tetanus toxoid first. This makes it easier to confuse these products in drug listings and means that you may not be able to search drug references, computer systems, and drug inventory/purchasing lists using the correct order of the component products. Pharmacists may also have difficulty finding the correct product when entering orders and selecting medications, and pharmacygenerated labels may differ from the way the components are listed by the manufacturer.