Safety of repeated doses of tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis vaccine in adults and adolescents

Abstract

In light of waning immunity to pertussis following receipt of tetanus toxoid, reduced diphtheria toxoid and acellular pertussis (Tdap) vaccine, maintaining protection may require repeated Tdap vaccination. We evaluated the safety of repeated doses of tetanus-containing vaccine in 68 915 nonpregnant adolescents and adults in the Vaccine Safety Datalink population who had received an initial dose of Tdap. Compared with 7521 subjects who received a subsequent dose of tetanus toxoid, reduced diphtheria (Td) vaccine, the 61 394 subjects who received a subsequent dose of Tdap did not have significantly elevated risk of medical visits for seizure, cranial nerve disorders, limb swelling, pain in limb, cellulitis, paralytic syndromes, or encephalopathy/encephalitis/meningitis. These results suggest that repeated Tdap vaccination has acceptable safety relative to Tdap vaccination followed by Td vaccination.

Keywords: pharmacoepidemiology; vaccination; whooping cough.

FIGURE 1

Adjusted* rate ratios of adverse events following toxoid and acellular pertussis (Tdap) vs Td as a second dose of tetanus-containing vaccine following an initial dose of Tdap, overall and stratified by years between vaccine doses*Overall risk ratios adjusted for age at first Tdap, years between first Tdap and second tetanus-containing vaccine, sex, study site, receipt of human papillomavirus vaccine, and hospitalizations in the prior year. Stratified risk ratios adjusted for age at first Tdap and years between first Tdap and second tetanus-containing vaccine.