An experimental dengue vaccine has shown promising results in a large ongoing phase 3 clinical trial, according to primary efficacy data published in the New England Journal of Medicine.
The study provided results from part one of the phase 3 randomised trial of a tetravalent dengue vaccine candidate (TAK-003) being carried out in regions of Asia and Latin America in which the disease is endemic.
Healthy children and adolescents aged four to 16 years were randomly assigned in a 2:1 ratio (stratified according to age category and region) to receive two doses of the vaccine or placebo three months apart.
Of the 20,071 participants given at least one dose of vaccine or placebo (safety population), 19,021 (94.8%) received both injections and were included in the per-protocol analysis.
The overall vaccine efficacy in the safety population was 80.9% (95% CI, 75.2-85.3; 78 cases per 13,380 [0.5 per 100 person-years] in the vaccine group vs. 199 cases per 6,687 [2.5 per 100 person-years] in the placebo group).
In the per-protocol analyses, vaccine efficacy was 80.2%, with 95.4% efficacy against dengue leading to hospitalisation.
Efficacy trends varied according to serotype.
The incidence of serious adverse events was similar in the vaccine group and placebo group (3.1% and 3.8%, respectively).