[Increased level of tetanus antibody twenty one years after a booster dose of tetanus vaccine].

We report the case of a 37 years old woman who asked for clinical advice about revaccination with tetanus toxoid. An adverse reaction to the last booster dose of vaccine, 21 years before, was recorded by a clinical doctor on the vaccination card. It was decided to evaluate serum antibody levels against tetanus and other diseases included in the Portuguese Vaccination Programme. The level of serum tetanus antitoxin (IgG) observed (6.4 IU/ml) corresponds to high protection against the disease and furthermore it is considered as a contraindication to vaccination due to the increased risk of adverse reactions to revaccination. The woman was susceptible to pertussis and diphtheria, and immune to measles, mumps and rubella. It was recommended that the woman should not receive tetanus toxoid and a new serological evaluation would be done 10 years after, in order to support the decision about revaccination.