Safety signal detected: Anaphylaxis after attenuated dengue vaccine (TAK-003) – Brazil, march 1, 2023-march 11, 2024

The aim was to describe cases of anaphylaxis following the Attenuated Dengue Vaccine (TAK-003) in Brazil, from March 1, 2023, to March 11, 2024. A descriptive study of anaphylaxis cases following TAK-003 was conducted, as reported in the National System of Surveillance of Adverse Events Following Immunization (AEFI). Percentages and notification rates of AEFI per million doses administered (DA) were calculated. In total, 380,358 doses of TAK-003 were administered, and 626 AEFI were reported. Of these, 85 were cases of immediate hypersensitivity, with 24 (63.1 cases per million) being anaphylaxis, including three anaphylactic shock. For 10 (41.7 %) cases, reactions began within 15 min after vaccination. No deaths related to anaphylaxis were reported. In light of the safety signal identification (increased frequency of anaphylaxis post-dengue vaccination), the Ministry of Health of Brazil published recommendations for intensifying actions for safe vaccination, including healthcare professional training and post-vaccination observation. •This study identified anaphylaxis as a safety signal for TAK-003 vaccines in adolescentes.•In most cases of anaphylaxis occurred 15 min after vaccination.•The signal identification allowed rapid and timely recommendation of risk prevention and mitigation measures in Brazil.