Dengue fever cases are prompting increased vigilance from health authorities and reinforcing the importance of preventative measures. In addition to controlling the Aedes aegypti mosquito, vaccination is being highlighted as a key strategy to reduce complications and hospitalizations caused by the virus.
During an interview on Monday, March 2, 2026, allergist Roney Mendes emphasized the role of immunization in combating the virus. “We have another safe, effective tool, which is vaccination against dengue. So, the dengue vaccine has been available in Brazil for a few years. It is effective and safe for people between 4 and 60 years of age,” he stated.
The Vaccine
Currently, Brazil offers the Qdenga vaccine, developed by Takeda and approved by the National Health Surveillance Agency (Anvisa) in 2023. The vaccine is being gradually incorporated into the National Unified Health System (SUS) schedule, according to criteria defined by the Ministry of Health, and is also available in the private healthcare sector.
The vaccine is recommended for individuals aged 4 to 60, regardless of prior infection, and the vaccination schedule consists of two doses administered three months apart.
According to Mendes, a primary benefit of the vaccine is protection against the more severe forms of the disease. “It has very high efficacy in preventing severe dengue, that is, hospitalization for severe dengue, hemorrhagic dengue,” he affirmed.
Clinical trials conducted in various countries have demonstrated a significant reduction in the risk of hospitalization and complications. The findings could inform future public health strategies for managing dengue outbreaks.
Mendes also highlighted the rigorous evaluation process before the vaccine was approved for widespread use. “This vaccine was extensively studied for four and a half years before it became available in a public network globally,” he explained.
He added that monitoring continued after approval. “After it became available for use in the public network, it has already been administered to millions of people. So, the safety data is enormous. Millions of people have been vaccinated and monitored, and We find no documented serious or frequent adverse events,” he added.
Despite its generally favorable safety profile, the vaccine has contraindications. It is not indicated for children under 4 years of age or adults over 60. Pregnant women and breastfeeding mothers should also not receive the vaccine.
Individuals with congenital or acquired immunodeficiency, including those undergoing chemotherapy or using immunosuppressant medications, as well as those with symptomatic HIV infection or significant impairment of the immune system, should avoid vaccination. It is also not recommended for those who have experienced a severe allergic reaction to components of the formula or to a previous dose. In cases of fever or acute illness, administration should be postponed until clinical recovery.
Experts emphasize that vaccination does not replace traditional prevention measures, such as eliminating standing water, using repellents, and installing physical barriers against mosquitoes. A combination of immunization and vector control is considered essential to reduce virus circulation and prevent overburdening healthcare services. Dengue can progress to severe conditions, particularly when warning signs such as intense abdominal pain, persistent vomiting, bleeding, and low blood pressure appear, reinforcing the importance of prevention and early diagnosis.
The ‘Revista Maranhão’ program, presented by journalist Keith Almeida, airs every Monday at 12:30 PM on TV Assembleia (digital open channel 9.2; Maxx TV, channel 17; and Sky, channel 309).
