Pertussis Immunization for Adolescents: What Are We Waiting for?

Immunization against pertussis (whooping cough) has been part of the routine childhood immunization program for over 50 years. Until 1997, a whole cell pertussis vaccine was used, most often combined with diphtheria and tetanus toxoids; in some jurisdictions it was combined with inactivated poliovirus vaccine and later withHaemophilus influenzaetype b (Hib)-conjugate vaccine. Vaccine doses were given at two, four, six and 18 months of age, and again at four to six years of age. Use of the whole cell vaccine in children seven years of age and older was not recommended because "the incidence and severity of the disease greatly decrease with age, and because adverse reactions are (may be) more common in older children and adults..." (1-3). Over a one-year period in 1997/98, all provinces in Canada began using an acellular pertussis vaccine, again combined with diphtheria and tetanus toxoids, inactivated poliovirus vaccine and Hib-conjugate vaccine. In 1999, an acellular pertussis vaccine that was combined with tetanus and diphtheria toxoids (TdaP) (Adacel, Aventis Pasteur, Canada) was licensed for use in individuals 12 to 54 years of age in Canada. In Germany, a similar adolescent and adult TdaP was licensed in 2000 (Boostrix, SmithKline Beecham, Belgium). With the availability of a TdaP product in Canada, should routine universal immunization against pertussis be provided for all adolescents and adults? Some of the key issues to be considered when answering this question are addressed in the questions and answers that follow. The focus of the present paper is on the adolescent population; however, similar issues about adult immunization need to be addressed by internal medicine and family practice practitioners.