Brazil produces a single-dose dengue vaccine developed at NIH
A quarter century of hard work has paid off for the National Institute of Allergy and Infectious Diseases (NIAID). In December, the Brazilian Health Regulatory Agency approved the world's first single-dose dengue vaccine, which is based on the research and clinical development of NIAID scientists. Brazil's Instituto Butantan has begun production of the new vaccine — known as Butantan-DV — and plans to deliver roughly 100 million doses to the country's Ministry of Health over the next three years.
Dengue fever is a mosquito-borne illness endemic in Brazil and widespread in tropical regions worldwide. Some refer to it as 'breakbone fever,' because it can cause severe aches and pains in the legs, joints and back.
Butantan-DV is "a live attenuated vaccine, which means it provides long-lasting immunity, and its production is cost effective," said NIAID's Dr. Stephen Whitehead, the lead inventor of the dengue vaccine technology, in a recent podcast. He explained that dengue virus has four serotypes (or strains), so his team developed separate vaccine candidates for each. Next, his team selected the candidates that worked best, tested them for about a decade, and then put them together in a single inoculation. "We're getting complete immunity against all four serotypes after the single dose."
This is important. After recovering from a dengue infection, individuals have long-term immunity against the serotype that infected them, but only two-to-three-month immunity against the remaining three serotypes. If they become infected with any of those three strains after their immunity wanes, they're at higher risk of developing a more severe version of the illness than if they'd never been infected at all.
Butantan, an organization linked to São Paulo State Department of Health, completed a five-year efficacy study and evaluated the vaccine in more than 16,000 volunteers living in 14 Brazilian states. In this study, Butantan-DV demonstrated nearly 75% efficacy overall, with 91% efficacy against severe dengue and 100% efficacy against dengue hospitalizations. Serious side effects were rare, most of the adverse reactions reported were mild to moderate, such as pain and redness at the injection site, headache, or fatigue.
Brazil's Ministry of Health estimates that, since the beginning of the 2000s, more than 20 million Brazilians have been affected by the disease. Each year, up to 400 million people are infected worldwide, according to the U.S. Centers for Disease Control and Prevention.
"A disease that has afflicted us for decades can now be confronted with a very powerful weapon: the single-dose vaccine from the Butantan Institute," stated Esper Kallás, MD, director of the Butantan Institute, in a press release. Butantan-DV is approved for use in ages 12 to 59 and is expected to be included in Brazil's National Immunization Program.
NIAID has licensed the vaccine technology to several companies and institutes in addition to Butantan for late-stage clinical evaluation and commercial development. Phase 3 trials are already underway for the vaccine in Southeast Asia (Merck) and India (Panacea Biotec), with Serum Institute of India planning to begin a new study in 2026.
"It is a success story both for the science and technology transfer," said Whitehead.
Updated April 22, 2026
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