Brazil Suspends Butantan Dengue Vaccine After 42 Severe Adverse Reports

Overview

• The Ministry of Health announced a temporary suspension on Monday and told states and municipalities to stop giving the Butantan vaccine and keep distributed doses refrigerated.
• About 501,000 doses had been given through January–May, with 3,703 reports of dengue-like symptoms, 42 cases flagged as having alarm signs, three classified as severe and two deaths under investigation.
• Anvisa, national pharmacovigilance committees (Cifavi and Ctai) and Instituto Butantan are conducting joint reviews of patient histories, lot tracking, cold-chain handling and clinical data, and officials say there is not yet evidence proving the vaccine caused the events.
• People who received the vaccine in the last 21 days will get active medical follow-up and should seek care for fever, intense abdominal pain, persistent vomiting, bleeding or signs of dehydration, while those vaccinated more than 21 days earlier are not being advised to take special action.
• The Butantan shot is Brazil’s first fully domestic dengue vaccine and showed strong efficacy in trials; the pause does not affect the Takeda Qdenga program for children and adolescents but could delay wider adult rollout pending the investigation's findings.