Diphtheria, tetanus, and pertussis immunizations in adults.

Although only few cases of diphtheria are reported annually in the United States, substantial numbers of adults have declining levels of protective serum antitoxin. A recent outbreak of diphtheria in Sweden emphasizes the importance of reimmunizing adults in diphtheria toxoid, included as part of routine use of tetanus/diphtheria toxoid. Tetanus is a completely preventable disease. Yet, most of the 60 to 100 annual cases of tetanus occur in older adults with no prior history of immunization. Tetanus immunization should be a routine part of medical care of all adults. Research currently is aimed at improving the efficacy and safety of pertussis vaccine. Future vaccines may be useful in protecting health care workers and other adults who have extensive contact with children against pertussis.