(HealthDay News) – A safe recombinant, live, attenuated tetravalent dengue vaccine has been deemed possible, according to a study published online Sept 11 in The Lancet.
Arunee Sabchareon, MD, from Mahidol University in Bangkok, and colleagues conducted an observer-masked, randomized, controlled, Phase 2b, proof-of-concept trial in healthy Thai schoolchildren, aged 4–11 years, to examine the efficacy of a recombinant, live, attenuated tetravalent dengue vaccine. Participants were randomly allocated to receive three injections of dengue vaccine (2,669 children; 2,452 children included in primary analysis), or control (rabies vaccine or placebo: 1,333 children; 1,221 children included in primary analysis) at zero, six, and 12 months, and were followed for 25 months.
The researchers found that there were 134 cases of virologically confirmed dengue. The vaccine protective efficacy against virologically confirmed dengue was 30.2%, and differed according to serotype. The vaccine was well tolerated; two years after the first dose, no evidence of safety signals was observed.
“Our study constitutes the first ever demonstration that a safe dengue vaccine is possible,” the authors write. “In the context of World Health Organization goals to reduce dengue mortality by at least 50% and the morbidity rate by at least 25% by 2020, this study represents a major milestone.”
Several authors are employed by and disclosed financial ties to Sanofi Pasteur, which funded the study.