A new single-dose dengue fever vaccine developed in Brazil was nearly 80% effective in a major trial. Other vaccines for the viral infection already exist, but they are costlier, require multiple doses, and are more complicated to administer. The vaccine could have a “huge impact” on strained public health systems, one analyst said.
The trial of Butantan-DV — developed by the São Paolo-based Butantan Institute — is believed to be the largest clinical trial ever in Brazil, which is among the countries most affected by the disease. The researchers hope to have full approval from the country’s health surveillance agency by 2025.
Cases of dengue, which spreads from mosquitoes to people, are skyrocketing around the world: The World Health Organization recorded a ten-fold surge in reported cases from 2000 to 2019. There were six million reported cases and more than 6,000 deaths in 2023, according to one estimate.
Climate change is contributing to rising dengue rates
A World Health Organization official called recent dengue outbreaks a “canary in the coal mine of the climate crisis.” The number of cases in Brazil alone this year is four times higher than the same period last year, according to government data, prompting authorities in Rio de Janeiro and Sao Paulo to declare public health emergencies.
“With temperatures and rainfall increasing, the mosquitoes that carry dengue viruses are extending their range,” the Yale School of the Environment said. Meanwhile, record temperatures exacerbated by El Niño “are a new and determining factor” behind dengue’s spread, the president of the National Council of Health Secretaries told AFP.
Citizens have some agency in preventing dengue, authorities say
During the COVID-19 pandemic, individuals didn’t have much control over public health outcomes. But “in the case of dengue much depends on the action of each citizen,” said Rio Mayor Eduardo Paes, encouraging residents to eliminate sources of still water that can become breeding grounds for mosquitoes. Insect repellent, and long, loose clothing, can also reduce risk, health authorities said.
Large outbreaks can overextend healthcare systems
Dengue isn’t as deadly as other mosquito-borne viruses, and many infected people never experience symptoms. But large outbreaks can “quickly overwhelm health care systems, worsening the toll of other illnesses and medical problems,” Vox reported.
“The cost of dengue in Brazil is absurd,” said one virologist who helped coordinate the latest vaccine trials, so the Brazilian government’s investment in the inoculation will have a “huge impact” on public health.