Brazil announced on Monday, June 8, 2026, a temporary suspension of the world’s first single-dose dengue vaccine after two suspicious deaths. Over 501,000 people received the shot this year. The vaccine was developed in Brazil and approved in November. It targets the mosquito-borne virus that causes fever, headaches, muscle pain, nausea and rashes, and can be fatal in rare instances. Of those vaccinated from January to May, 3,703 showed dengue-like symptoms and 42 had more serious reactions. Three severe cases were recorded, including the deaths of a 58-year-old man and a 48-year-old woman. Health authorities noted there is insufficient evidence of a direct link but called the events a warning signal. Vaccination was paused as a precaution. Earlier trials with 16,000 volunteers showed 91.6 percent efficacy against severe disease. Brazil reported over 6,000 dengue deaths in 2024.
