Dengue vaccines lower viremia rates and hemorrhagic fever risk compared to placebo in a meta-analysis of 175434 participants

Over recent decades the incidence of dengue has increased on a global scale and in 2023 reached unprecedented levels. One potential promising approach to prevent dengue and reduce dengue symptoms is vaccination. We systematically searched PubMed/Medline, Scopus, Embase, Web of Science, Cochrane, and Lilacs databases from inception to the 27 of July 2025 (PROSPERO registration CRD42024579006). Outcomes were pooled and expressed as odds ratio (OR) with corresponding 95 % confidence intervals (CI). Meta-analysis was conducted for each outcome using Review Manager and the grading of evidence was carried out using the GRADE. We included 42 studies with a total of 175,434 participants. Efficacy of vaccine was demonstrated by the lower rate of viremia OR = 0.35, 95 %CI (0.25, 0.48), p < 0.00001, hemorrhagic fever OR = 0.16, 95 %CI (0.09, 0.28), p < 0.00001and high percentage of antibody production. In terms of safety, all vaccines showed promising results with no significant difference in serious adverse events when compared to placebo group. A higher rate of reaction at the injection site was reported only for swelling, erythema, pruritus, and rash. Asthenia, myalgia, arthralgia, malaise, nausea, and neutropenia were identified systemic side effects reported with a higher rate in the vaccinated group. Our findings suggest that dengue vaccination is potentially both safe and efficacious.