Diphtheria-Tetanus—Acellular Pertussis (DTaP) Vaccine-Reply

In Reply. —The efficacy rate attributed to Tripedia in the article is based on data from a study in Germany 1 reported to the Vaccines and Related Biologics Products Advisory Committee in January 1996. That study used a different case definition of pertussis from the now generally accepted WHO case definition on which the efficacy rate stated in the Tripedia labeling is based. While it is true that Tripedia has not yet been approved for the fifth dose following priming with Tripedia, from the practicing pediatrician's position, the point is moot. Infants who started receiving Tripedia this summer, when the vaccine was licensed for the first 3 doses, will not be candidates for a 5th dose for 4 years. By then, the FDA expects to have accumulated sufficient data to warrant licensure of the fifth dose. There is no question that there are untoward reactions with other acellular vaccines besides Infanrix. But