Phase 3 RCT: Butantan-DV Dengue Vaccine is Safe and Shows 67.3% Efficacy Over 3.7 Years in Participants Aged 2–59 Years – Lancet Infect Dis

Study Design and Population: This double-blind, randomized, placebo-controlled, phase 3 trial conducted in Brazil evaluated the efficacy and safety of the Butantan-dengue vaccine (Butantan-DV) in 16,235 healthy participants aged 2–59 years. Participants, who had not previously received a dengue vaccine, were randomly assigned to receive either a single dose of Butantan-DV or a placebo and were followed up for an average of 3.7 years.

Main Findings: The study found that Butantan-DV demonstrated 67.3% efficacy against virologically confirmed dengue (VCD) caused by any dengue virus serotype, with no cases of VCD caused by DENV-3 or DENV-4. The proportions of serious adverse events were similar between the vaccine and placebo groups, indicating that the vaccine was generally well tolerated.

Implications for Practice: The results support the potential of the Butantan-DV vaccine as an effective intervention for preventing symptomatic dengue, particularly from DENV-1 and DENV-2, across a broad age range regardless of dengue serostatus. Continued development and monitoring are warranted to confirm long-term efficacy and safety.

Reference: Nogueira, M. L., et al. (2024). Efficacy and safety of Butantan-DV in participants aged 2–59 years through an extended follow-up: results from a double-blind, randomised, placebo-controlled, phase 3, multicentre trial in Brazil. The Lancet Infectious Diseases. DOI: https://doi.org/10.1016/S1473-3099(24)00376-1.