The mosquito-borne disease killed 6,000 people worldwide last year.
In Rio de Janeiro, adult volunteers were vaccinated against dengue this Friday as part of a study aimed at immunizing 20,000 adults, aged 18 to 40.
Data will be collected for two years to observe changes in the behavior of the virus between vaccinated and unvaccinated people.
According to an official from the Ministry of Health, this study could serve as a basis for a global health policy.
The disease killed 6,000 people worldwide in 2023. Brazil is one of the countries with the most cases.