Prevalence of hyperimmunization against tetanus in a national sample of 18-26 year old immune subjects in Italy.

Prevalence of tetanus hyperimmunization was estimated among 3217 immune subjects to be approximately equal to 11%. Hyperimmunization was associated with age, area of residence and health care availability. Indiscriminate administration of booster doses of tetanus vaccine could result in some areas in unnecessary revaccinations and possibly hypersensitivity reactions. The immunization policy regarding booster doses should be based on factual evidence and not on rigid recommendations.