On March 15, 2005, the Vaccines and Related Biological Products Advisory Committee of the Food and Drug Administration recommended the approval of 2 tetanus toxoid, reduced diphtheria toxoid, and reduced acellular pertussis, adsorbed (Tdap) vaccines. These vaccines, Adacel and Boostrix, are the products of Sanofi Pasteur and GlaxoSmithKline, respectively. Food and Drug Administration licensure of these vaccines occurred in May/June 2005.Both of these vaccines have been studied extensively for immunogenicity and reactogenicity in large studies in the United States and around the world. In addition, Adacel is licensed and used in Canada, and Boostrix is licensed and used in several countries around the world. The comparative composition of the 2 vaccines is presented in Table 1.In general, both vaccines have similar reactogenicity profiles as adult-formulated diphtheria and tetanus toxoids. After a single dose, both vaccines elicit vigorous antibody responses to the antigens that they contain. Specifically, these responses are significantly greater than those observed in infants at 7 months of age after 3 doses of the 2 manufacturers' pediatric diphtheria-tetanus-acellular pertussis (DTaP) vaccines (ie, Daptacel and Infanrix). These bridging data indicate that both vaccines will be efficacious in adolescents and adults. In addition, efficacy in adolescents and adults has been demonstrated with an experimental vaccine that contained the pertussis antigens of Boostrix without diphtheria and tetanus toxoids.1The licensed indications of the 2 vaccines are different. Specifically, Adacel is approved for adolescents and adults aged 11 through 64 years, whereas Boostrix is approved for preadolescents and adolescents 10 through 18 years of age.The increase in reported pertussis in recent years and the recognition of the contribution of adolescents and adults to this increase has resulted in numerous publications in both the lay press and the medical literature.2–4 Of major concern, for which much effort has been directed during the last 5 years, is how best to use these new vaccines. The Global Pertussis Initiative5 addressed the complexities of pertussis beginning in 2001; more recently, the Advisory Committee on Immunization Practices (ACIP) has had a working group on pertussis, and the National Immunization Program of the Centers for Disease Control and Prevention has formed an extensive panel on US priorities for pertussis prevention and control. In addition, both manufacturers have had scientific meetings addressing how to use the new vaccines.Pertussis is a significant disease in adolescents and adults, with ≥1 million cases annually in the United States, and recent data indicate that these cases are the major source for severe disease and frequent deaths in young infants.Various strategies for the control of pertussis were presented recently in the Global Pertussis Initiative summary publication. On June 29, 2005 the ACIP recommended the use of Tdap vaccines for adolescents 11 to 18 years of age. Their recommendation also stated that Adacel is available for adult use in individuals up to 64 years of age. More specific recommendations for adult immunization will be discussed at the upcoming October ACIP meeting.Although this approach can be looked on as a first stage, it is very disappointing to me because it will have only a minimal effect; it is being put forward because no one is willing to address the fundamental issue, which is the dismal failure of adult immunization in the United States. It is a national tragedy that ∼35000 people, mainly adults, die each year from influenza, a vaccine-preventable disease, and adults still die from tetanus, another vaccine-preventable disease.Bordetella pertussis illness is endemic in adolescents and adults of all ages, so immunization of adolescents will not interrupt the transmission of B pertussis to infants.2,3 It is my belief that a Tdap immunization program starting in preadolescence and given at 10-year intervals to adults will control both adolescent and adult pertussis as well as the transmission of B pertussis to unimmunized infants.4 This approach might also eliminate the circulation of B pertussis in the United States. This suggestion may be looked on by many as a pie-in-the-sky vision, but it should be recalled that the circulation of Corynebacterium diphtheriae as well as the control of diphtheria was brought about by immunizing both children and adults in the 1930s and 1940s.Our number one priority today should be good public health for adults. We need to find a method to ensure that all adults get the immunizations they need, including protection against B pertussis infection.