One Shot, Big Shift – Brazil’s Homegrown Breakthrough Against Dengue

It’s a rare piece of good news. A single-dose dengue vaccine developed in Brazil as part of an international collaboration protected people against at least two strains of the virus for five years or longer, and did so safely. 

The vaccine was already being tested across Brazil and the findings helped boost confidence in its use. 

“This is a big deal,” says Dr. Andre Siqueira, Head of the Dengue Global Program at the Drugs for Neglected Diseases Initiative (DNDI).  

Dr. Siqueira, who is also an Infectious Diseases Consultant at Brazil’s Instituto Nacional de Infectologia Evandro Chagas, a hospital that is part of the Oswaldo Cruz Foundation (Fiocruz), helped develop the vaccine. He chatted with One World, One Health about the work in 2024. 

The new vaccine worked almost perfectly to keep people from being hospitalized with severe dengue symptoms, Dr. Siqueira and the team reported in Nature Medicine.  

That’s a big deal. Dengue can cause terrible symptoms, including severe abdominal pain, internal bleeding, severe muscle aches, and long term fatigue. From January 2025 to January 2026, dengue killed more than 4,000 people. 

The only other dengue vaccines currently available are a two-dose formula made by Japanese manufacturer Takeda and Sanofi’s Dengvaxia, which the company is discontinuing because of a lack of demand. 

In this episode, Siqueira updates host Maggie Fox about the latest findings on the new vaccine’s efficacy and its rollout in Brazil.