Implications of the diphtheria epidemic in the Former Soviet Union for immunization programs.

The massive diphtheria epidemic in the former Soviet Union provides important lessons for all diphtheria immunization programs: It is important to achieve a high level of childhood immunization, maintain immunity against diphtheria in older age groups, and use anti-epidemic measures, including immunization, to control epidemics in the early phase. The immunization coverage among children should be at least 90%. Further studies are needed to elaborate the most effective strategy to maintain immunity against diphtheria in adults (periodic booster doses, immunization of selected age groups in health care settings, use of Td [tetanus-diphtheria toxoids with reduced diphtheria toxoid content] vaccine instead of monovalent tetanus toxoid whenever tetanus toxoid is indicated [e.g., in treatment of wounds or in school-based immunization programs]). Efforts should be undertaken to monitor diphtheria immunity in different groups by conducting age-specific serologic studies.