Adverse event occurrence following use of tetanus, diphtheria and acellular pertussis adsorbed vaccine – Tdap –, São Paulo, SP, Brazil, 2015-2016

Abstract

Objective: to describe occurrence of adverse events following immunization (AEFI) with Tdap vaccine during pregnancy. Methods: this was a descriptive study using data from reports by participants in an effectiveness and immunogenicity study conducted in two hospitals in São Paulo, SP, Brazil, from 2015 to 2016. Results: of the 201 mothers included in the study, 48 (23.9%) had at least one AEFI; 60 symptoms related to Tdap use were identified – pain (22.4%), swelling (2.5%), fever (1.5%), somnolence (1.0%), redness (0.5%), vomiting (0.5%), headache (0.5%), local reaction (0.5%), and fatigue (0.5%); no rare, very rare, or extremely rare adverse events were reported; all events were considered to be expected, as they are described in the vaccine package insert; outcome of all events was recovery without sequelae. Conclusion: Tdap vaccine in the form adopted by the National Immunization Program is safe; no unexpected adverse events were identified among vaccinated pregnant women.