Brazilian Single-Dose Dengue Vaccine Shows 80.5% Efficacy Against Hospitalization in Five-Year Phase 3 Trial
核心洞察
Brazil's Butantan Institute developed a single-dose tetravalent dengue (搜索) vaccine that demonstrated 80.5% efficacy against hospitalization for dengue over five years in a phase 3 clinical trial.
The vaccine showed 65.0% overall efficacy against symptomatic dengue (搜索), with higher protection in previously infected participants (77.1%) compared to dengue-naive individuals (58.9%).
The Brazilian Health Regulatory Agency (搜索) approved Butantan-DV (搜索) in November 2025 for use in people aged 12 to 59 years, marking a significant milestone in dengue (搜索) prevention.
Brazil's Butantan Institute has achieved a significant breakthrough in dengue (搜索) prevention with its single-dose tetravalent dengue vaccine, demonstrating 80.5% efficacy against hospitalization in a five-year phase 3 clinical trial published in Nature Medicine. The vaccine, known as Butantan-DV (搜索), represents a major advancement in addressing the growing global dengue burden.
Trial Design and Participants
The double-blind, placebo-controlled trial enrolled 16,235 participants aged 2 to 59 years across 16 Brazilian research centers from 2016 to 2019. Participants were randomly assigned to receive either the live, attenuated, tetravalent vaccine (10,259 people) or placebo (5,976 people). The study's primary objective was to evaluate vaccine effectiveness against symptomatic dengue (搜索) 28 days post-vaccination due to any dengue virus serotype, regardless of participants' baseline serostatus.
Efficacy Results
Over the five-year follow-up period from 2016 to 2024, the vaccine demonstrated robust protection across multiple endpoints. The overall vaccine efficacy against symptomatic dengue (搜索) was 65.0% (95% CI: 57.8–71.0%). Notably, no vaccinated participants were hospitalized during the entire study period.
The vaccine showed differential efficacy based on participants' prior dengue (搜索) exposure. In dengue-experienced participants, vaccine efficacy reached 77.1% (95% CI: 67.6–83.9%), while in dengue-naive participants, efficacy was 58.9% (95% CI: 48.0–67.6%).
Serotype-Specific Protection
The vaccine demonstrated varying levels of protection against different dengue (搜索) virus serotypes. Efficacy against DENV-1 was 73.0% (95% CI: 64.3–79.7%), while protection against DENV-2 (搜索) was 55.7% (95% CI: 42.3–66.1%). Cases of DENV-3 (搜索) and DENV-4 (搜索) were not observed during the study period.
Safety Profile
The vaccine demonstrated a favorable safety profile throughout the five-year follow-up. The most commonly reported solicited systemic adverse event was headache, occurring in 36.7% of vaccine recipients compared to 31.1% of placebo recipients, with most cases being grade 1. The proportions of participants experiencing unsolicited vaccine-related adverse events, including serious adverse events, were comparable between the intervention and placebo groups.
Regulatory Approval and Clinical Significance
The Brazilian Health Regulatory Agency (搜索) approved Butantan-DV (搜索) in November 2025 for use in people aged 12 to 59 years. This approval represents a crucial milestone in dengue (搜索) prevention, particularly given the disease's expanding global footprint.
As the study authors noted, "The spread of dengue (搜索) has greatly increased worldwide over the past two decades." They emphasized the complex nature of dengue immunity, explaining that "Natural infection by one dengue virus serotype allows homotypic protection against the same strain but subsequent heterotypic infection by another of the four DENV serotypes can result in severe disease."
Meeting Primary and Secondary Endpoints
The trial successfully met both its primary and secondary objectives, with the lower bound of the two-sided 95% confidence interval for vaccine efficacy exceeding the prespecified threshold of 25%. The vaccine's 80.5% efficacy against dengue (搜索) with warning signs or severe dengue (95% CI: 50.8–92.4%) represents a particularly significant achievement in preventing the most serious manifestations of the disease.
The Butantan-DV (搜索) vaccine addresses a critical unmet medical need for a single-dose dengue (搜索) vaccine that protects against all four dengue virus serotypes across a wide age range, regardless of prior dengue exposure status. The sustained efficacy over five years and the absence of hospitalizations among vaccinated participants underscore the vaccine's potential to significantly reduce the global burden of dengue disease.