Inadvertent administration of DTP and DT after age six as recorded in the Vaccine Adverse Event Reporting System

Abstract

Objective: Diphtheria and tetanus toxoids and whole-cell pertussis vaccine (DTP) and pediatric diphtheria and tetanus toxoids (DT) are not recommended for individuals > or = 7 years of age due to increased adverse reactions and the low pertussis case-fatality rate. Our objective was to determine if reactions to DTP and DT in individuals > or = 7 years of age were due to administration of pediatric DTP or DT instead of adult tetanus and diphtheria toxoids (Td), after adjusting for database inaccuracies.

Methods: We analyzed data from the Vaccine Adverse Event Reporting System (VAERS) reported from July 1, 1990 through March 31, 1992. Vaccine manufacturers were contacted to verify whether lot numbers indicated DTP or DT.

Results: According to VAERS's data, among individuals 7 years of age or older, 26 received DTP and 77 received DT. When lot numbers were compared with manufacturers' records, 8 of the 77 DT doses were confirmed; 11 had incorrect or missing lot numbers; one was a duplicate; 56 were Td; and one was neither DT nor Td. Alleged adverse reactions included fever, headache, and convulsions.

Conclusion: Individuals > or = 7 years of age are inadvertently receiving DTP or DT and may be unnecessarily experiencing adverse reactions. The 1992 VAERS database offers opportunities to investigate hypotheses but should be interpreted with caution due to inaccuracies in reporting and duplicate entries.