Tdap vaccine: current indications for adolescent and adult patients in the United States.

Despite the availability of a tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccine in the United States since 2005, the vaccine remains underutilized and perhaps misunderstood by many physicians. Pertussis continues to be a major public health problem, with adults being the primary source of infectious transmission to unprotected infants. Consequently, the Centers for Disease Control and Prevention's Advisory Committee on Immunization Practices has expanded the indications for the Tdap vaccine. In addition, the vaccine can be safely administered regardless of the time since the patient's last tetanus-diphtheria booster. Widespread use of the Tdap vaccine-especially in health-care workers, adolescents, and adults aged 19 to 64 years-should greatly reduce the incidence of Bordetella pertussis infection in the United States. The recent Food and Drug Administration approval of the Tdap vaccine for individuals aged 65 years or older should increase the use of this vaccine.