Brazil has temporarily halted its national dengue vaccination drive after two people — a 48-year-old woman and a 58-year-old man — died and 42 others suffered severe adverse reactions including intense abdominal pain, persistent vomiting, and bleeding. The vaccine, developed by the Butantan Institute in São Paulo and notable as the world's first single-dose dengue shot, had been administered to around 501,000 people, primarily health workers, since the campaign launched in February 2026. Health Minister Alexandre Padilha described the pause as a precautionary pharmacovigilance measure, stressing that a causal link to the deaths has not been established and that the suspension does not invalidate the vaccine's efficacy, which clinical trials showed at roughly 75% overall and 100% against hospitalisation.