Dengue Bill Brieger | 16 May 2025 06:19 pm
Brazil is Facing another Dengue Outbreak
Bradley Blankenship contributed a blog posting on the continued challenges of Dengue in Brazil for the course, “Social & Cultural Basis for Community and Primary Health Programs,” at the Johns Hopkins Bloomberg School of Public health. Below are his concerns and observations.
A child receiving the dengue vaccine in Brazil, courtesy Nature.com
Brazil is currently facing a record-breaking number of dengue cases. In 2024, the country reported 5.1 million cases, with over 2,800 deaths associated with dengue. This is an all-time high for the country and surpasses projections. As a response, the government attempted changes to its national immunization program with the implementation of the Qdenga vaccine (Takeda’s new dengue vaccine). In fact, Brazil secured the entire global supply of Qdenga in 2024 to address rising numbers of cases and complications. This campaign is a crucial step for Brazil, but it is not without its challenges.
Safety and trust are major issues with new Dengue vaccine rollouts, as Qdenga follows a controversy in the Philippines after a previous vaccine, Dengvaxia, was withdrawn when it was found to increase the risk of severe Dengue in dengue-naïve children. This controversial rollout eroded public confidence in dengue vaccines. In contrast, Qdenga has been proven safe, even for those who have never been infected, and does not require pre-vaccination testing. This is a critical advantage of Qdenga and a crucial point to consider when rebuilding trust.
The global supply of Qdenga is limited, though, and Takeda is only able to produce about 6 million doses each year. This means that only 3 million people may receive the two-dose series recommended by the developers. The initial campaign, therefore, only covers a fraction of Brazil’s population. Furthermore, two-dose uptake by the population is also a concern, with only 714,000 reported second doses administered vs 2.16 million first doses reported, underlining the need for better follow-up and public education.
Moving forward, we need the Brazilian Ministry of Health to act on multiple fronts to address the dengue outbreak in Brazil. We need expanded access to Qdenga vaccines by securing more doses and broadening eligibility, rebuilding vaccine trust and compliance through education and community partnerships, and further support for the development of single-dose vaccine being developed by the Butantan Institute that would allow for improved compliance and domestic production, ultimately securing the ability to produce more vaccines as needed.
With millions of Brazilians vulnerable to dengue fever, decisive leadership from Brazil’s Ministry of Health is essential to adequately address the outbreak.