Novel Single-Dose Dengue Vaccine Shows High Efficacy in Phase 3 Trial

The double-blind trial, spanning a 3-year enrollment period, included 16,235 participants randomly assigned to receive Butantan-DV or a placebo. Stratification was based on age groups (2 to 6 years, 7 to 17 years, and 18 to 59 years), with a planned 5-year follow-up. The primary efficacy endpoint was the prevention of symptomatic, virologically confirmed dengue of any serotype occurring more than 28 days after vaccination. The trial also aimed to assess safety, with primary safety endpoints evaluated up to day 21 post-injection.

• After 2 years of follow-up, Butantan-DV demonstrated an overall vaccine efficacy of 79.6%.

• Notably, efficacy was 73.6% among participants with no previous dengue exposure and an impressive 89.2% among those with a history of exposure.

• Age-specific efficacy revealed promising results: 80.1% in participants aged 2 to 6 years, 77.8% in those 7 to 17 years, and 90.0% in the 18 to 59 years age group.

• The vaccine showed efficacy against DENV-1 at 89.5%, and DENV-2 at 69.6%, with no detection of DENV-3 and DENV-4 during the follow-up period.

• However, solicited systemic vaccine-related adverse events within 21 days were more common with Butantan-DV compared to the placebo (58.3% vs. 45.6%).

This groundbreaking study reveals that a single dose of Butantan-DV effectively prevents symptomatic DENV-1 and DENV-2, irrespective of participants' dengue serostatus at baseline, over a 2-year follow-up. The vaccine demonstrates high efficacy across various age groups and serotypes, marking a significant advancement in dengue prevention.

Reference:

Kallás, E. G., Cintra, M. A. T., Moreira, J. A., Patiño, E. G., Braga, P. E., Tenório, J. C. V., Infante, V., Palacios, R., de Lacerda, M. V. G., Batista Pereira, D., da Fonseca, A. J., Gurgel, R. Q., Coelho, I. C.-B., Fontes, C. J. F., Marques, E. T. A., Romero, G. A. S., Teixeira, M. M., Siqueira, A. M., Barral, A. M. P., … Nogueira, M. L. Live, attenuated, tetravalent Butantan–dengue vaccine in children and adults. The New England Journal of Medicine,2024;390(5):397–408. https://doi.org/10.1056/nejmoa230179