[Adverse reactions after repeated doses of anti-tetanus vaccine: scientific evidences]

The possible risk of hyperimmunization after tetanus vaccination is currently discussed after the National Vaccine Prevention Plan 2017-2019 confirmed the recommendation of a booster dose every ten years. Due to the ubiquitous nature of tetanus spores and the inability to obtain herd-immunity through vaccination, efforts to reduce the incidence of tetanus aim at eliminating the disease. The only way to prevent infection is vaccination followed by recommended periodic booster doses. Between 2012 and 2016, Italy notified 45% (252/564) of all cases reported by the 26 EU Member States, most of them in the over 65 age group, generally women in the rural areas. The recommendation of the antipertussis vaccine, combined with anti-tetanus, in pregnancy and the indications for antitetanic prophylaxis by vaccination or specific immunoglobulins in emergency setting, gives rise to doubts about the risk of hyperimmunization. Studies generally agree on the safety of diphtheria-tetanus-pertussis combined vaccines during the third trimester of pregnancy, and the time elapsed since the previous tetanus vaccination seems not to be related to significant differences in the incidence of adverse events or obstetrical complications. In the emergency wards, given the relatively high incidence of tetanus in Italy, the risk/benefit ratio often leads to prefer vaccination to no-intervention. The administration of tetanus immunoglobulins in subjects not vaccinated in the last 10 years seems justified by the epidemiology of tetanus in Italy.