Loading...
Dengue virus (DENV) infection causes millions of cases and up to 40,000 deaths annually worldwide. To test the safety and efficacy of Butantan-DV, a live, attenuated dengue vaccine targeting all four DENV serotypes, investigators in Brazil randomized 16,235 participants (age range, 2–59 years) 2:1 to receive vaccine or placebo; the primary outcome was virologically confirmed symptomatic dengue (assessed with passive surveillance).
Evidence of preexisting immunity to any DENV serotype was present in 49.6% of participants and rose with age. During 2 years' follow-up, dengue occurred in 135 participants (59 DENV-1 and 76 DENV-2). Vaccine efficacy (VE) at preventing dengue was 79.6% (any serotype), 89.5% (DENV-1), and 69.6% (DENV-2). VE was 73.6…