Dengue vaccines in the real world: why long-term surveillance matters

On June 8, 2026, Brazil temporarily discontinued its current vaccination strategy with the single-dose dengue vaccine Butantan-Dengue Vaccine (Butantan-DV) when rare events after vaccination were under investigation.1–3 This pause should neither be interpreted as evidence of vaccine failure nor diminish the importance of a key advancement in dengue prevention. Rather, the pause highlights a broader lesson: for dengue vaccines, conclusions regarding efficacy, safety, and public-health benefit should not stop at regulatory approval.