Serologic immunity to diphtheria and tetanus in the United States

Ann Intern Med. 2002 May 7;136(9):660-6. doi: 10.7326/0003-4819-136-9-200205070-00008.


Background: Serologic data on diseases that are preventable by vaccine are useful to evaluate the success of immunization programs and to identify susceptible subgroups.

Objective: To provide national estimates of immunity to diphtheria and tetanus by measurement of serum antibody levels.

Design: Examination of data from the Third National Health and Nutrition Examination Survey, a representative cross-sectional sample of the U.S. population.

Setting: 89 randomly selected locations throughout the United States.

Participants: 18 045 persons 6 years of age or older who were examined from 1988 to 1994.

Measurements: Serum samples obtained at a single time point were tested for diphtheria and tetanus antitoxin.

Results: Overall, 60.5% of Americans 6 years of age or older had fully protective levels of diphtheria antibody (> or =0.10 IU/mL) and 72.3% had protective levels of tetanus antibody (> 0.15 IU/mL). Ninety-one percent of Americans 6 to 11 years of age had protective levels of both diphtheria and tetanus antibody; this proportion decreased to approximately 30% among persons 70 years of age (29.5% for diphtheria and 31.0% for tetanus). Adult Mexican-Americans were slightly less likely to have protective levels of antibody to both toxins. Only 47% of persons 20 years of age or older had levels that were protective against both diseases, and only 63% of adults who were protected against tetanus were also protected against diphtheria.

Conclusions: A substantial proportion of adults in the United States do not have antibody levels that are protective against diphtheria and tetanus. In addition, although the recommended vaccine is a combination of tetanus and diphtheria, only 63% of adults with protective antibody to tetanus also had protective antibody to diphtheria.

MeSH terms

  • Adolescent
  • Adult
  • Age Distribution
  • Aged
  • Antibodies, Bacterial / blood*
  • Child
  • Cross-Sectional Studies
  • Diphtheria / immunology*
  • Diphtheria / prevention & control
  • Diphtheria-Tetanus Vaccine
  • Female
  • Humans
  • Male
  • Middle Aged
  • Prevalence
  • Socioeconomic Factors
  • Tetanus / immunology*
  • Tetanus / prevention & control
  • United States / epidemiology


  • Antibodies, Bacterial
  • Diphtheria-Tetanus Vaccine