06/08/2026 | Ministry of Health

https://www.gov.br/saude/pt-br/assuntos/noticias/2026/junho/ministerio-da-saude-descontinua-temporariamente-estrategia-atual-de-vacinacao-do-butantan-contra-dengue 

The measure was adopted as a precaution until the conclusion of the investigation of 42 rare cases with warning signs that had not been observed in the clinical study.

The Ministry of Health announced, this Monday (June 8), the temporary discontinuation of Butantan-DV's current dengue vaccination strategy. With this, the use of the immunizing agent is paralyzed for the investigation of rare, unexpected events incompatible with the clinical study conducted for the vaccine's approval.

The measure, adopted as a precaution and based on consensus between the Ministry of Health and the National Health Surveillance Agency (Anvisa), comes after the registration of 42 cases with warning signs, such as intense abdominal pain, persistent vomiting, and bleeding. Among these, three were classified as serious, including two deaths. The identification of these episodes was made through pharmacovigilance – a standard monitoring procedure adopted whenever a new product of this type begins to be used in the Unified Health System (SUS).

These are rare events that correspond to 0.008% of a total of 500,000 doses administered up to May 30th – and there is still no conclusive result regarding their correlation with the vaccine.

"This discontinuation has a purpose. First, it is a precautionary measure that should always guide those who respect life and those who respect science, even more so when we are talking about vaccination. Second, it allows the Ministry of Health, Anvisa (Brazilian Health Regulatory Agency), and the Butantan Institute to deepen the investigation of the cases, especially the registered deaths, for which there is still insufficient information to establish a causal relationship with the vaccine," highlighted the Minister of Health, Alexandre Padilha.

The vaccination strategy with the Butantan vaccine was aimed at primary healthcare professionals and, more broadly, at the 15-49 age group in three cities – Botucatu/SP, Maranguape/CE, and Nova Lima/MG – and the Araguaína region in Tocantins. The action began in January of this year.

Surveillance

The identification of warning signs after the introduction of a vaccine into the healthcare system follows international pharmacovigilance protocols.

Before being incorporated into the Brazilian Unified Health System (SUS), the Butantan-DV vaccine underwent all the evaluation stages required by regulatory bodies, with results demonstrating its safety and efficacy.

The decision to temporarily suspend the application of the immunizing agent was made after discussions with the Interinstitutional Committee for Pharmacovigilance of Vaccines and other Immunobiologicals (Cifavi) and the Technical Advisory Chamber on Immunization (Ctai), bodies composed of representatives from the Ministry of Health, Anvisa (Brazilian Health Regulatory Agency), and specialists.

It is important to highlight that this measure does not invalidate the vaccine's efficacy nor alter the evidence of protection observed to date. Those who have already been immunized remain protected, and epidemiological surveillance continues to monitor the vaccinated population.

For those who have already received the vaccine, the recommendation is to monitor their health status for 21 days after application. In case of symptoms such as fever, intense abdominal pain, persistent vomiting, bleeding, dizziness, excessive drowsiness, signs of dehydration, or worsening of general condition, medical attention should be sought immediately.

From now on, health teams will reinforce surveillance of vaccinated patients who present dengue symptoms, paying special attention to recognizing warning signs and signs of severity. They should also intensify case reporting, activate local surveillance, and ensure immediate referral for clinical care when necessary.

Combating Dengue

The Ministry of Health maintains all other dengue control strategies in operation, with the aim of reducing virus circulation, preventing severe cases, decreasing hospitalizations, and avoiding deaths.

By the end of May of this year, the country had registered a 94% decrease in the number of cases compared to the same period in 2024. There were 365,000 probable cases, well below the 5.8 million recorded in the same period of 2024. Regarding deaths, the reduction was 97%, with 178 deaths recorded in 2026 and more than 6,300 in 2024.

Among the strategic measures adopted by the Ministry of Health are the strengthening of epidemiological surveillance, continuous monitoring of suspected and confirmed cases, identification and elimination of breeding grounds for the Aedes aegypti mosquito, permanent public awareness campaigns, and technical and financial support to states and municipalities for vector control actions.

The Ministry also maintains the distribution of insecticides, larvicides, and equipment to local surveillance teams, in addition to the continuous training of health professionals for early diagnosis and proper patient management. Another important front is the laboratory monitoring of circulating dengue virus serotypes, allowing for faster responses to increased transmission in certain regions.

Public participation remains fundamental to controlling the disease. The recommendation is to eliminate containers that can accumulate stagnant water, keep water tanks properly closed, clean gutters, dispose of waste correctly, and allow access for disease control agents when necessary.

Questions and Answers

Why is the Butantan Institute's dengue vaccine being discontinued?

The Ministry of Health has temporarily discontinued the current strategy for administering the Butantan-DV vaccine as a precaution. 501,000 doses were administered to primary healthcare professionals working on the front lines of the Brazilian Unified Health System (SUS), and to people aged 15 to 59 in the municipalities of Nova Lima (MG), Maranguape (CE), and Botucatu (SP), as well as the Araguaína region (TO). The epidemiological surveillance monitoring system functioned and detected an alarm signal that needs further investigation. The decision will allow for more in-depth investigations to assess the signals and does not invalidate the vaccine's effectiveness (clinical studies showed an overall efficacy of 65% and 80.5% for severe cases).

The Ministry of Health acted based on concrete data from the pharmacovigilance system—not on rumors, unfounded associations, or political pressure. It is the opposite of denialism: science being applied in real time, with transparency.

The Brazilian Unified Health System (SUS) continues to offer dengue immunization for children and adolescents aged 10 to 14 with the Qdenga vaccine, produced in Japan and offered in the public network since 2024. Approximately 8 million doses have already been administered in Brazil, with visible impacts on disease control.

What problem was found?

An alarm signal was detected by the pharmacovigilance of the health network. Of 501,000 people who received the vaccine, 42 cases of rare and unexpected reactions were recorded (corresponding to 0.008% of the total) that had not been identified in clinical studies nor predicted in the package insert. Three serious cases were also identified, two of which resulted in death. None of these occurred in the three cities and region where vaccination was expanded to the population.

It cannot be stated that the deaths were caused by the vaccine, but it was considered a warning sign that justifies a thorough investigation. Possible comorbidities, risk factors, and other situations that may have contributed to the deaths will be verified.

How was the vaccine approval process?

The Butantan Institute worked on developing the vaccine for approximately 20 years, having licensed the seed technology from the United States National Institutes of Health (NIH). Phase 1, 2, and 3 clinical studies were conducted, according to current protocols. More than 11,000 volunteers were vaccinated and monitored for 5 years to verify efficacy and safety. With this data, Anvisa authorized the production and commercialization of the vaccine in December 2025.

The vaccine showed an overall efficacy of 65% against the disease and an efficacy of 80.5% for more severe cases.

Is the vaccine safe?

Of more than 500,000 doses administered, rare and unexpected effects appeared in 0.008% of people who received the vaccine. The vaccine went through all the required stages before being approved: pre-clinical and clinical development with 11,000 vaccinated individuals, safety, immunogenicity, and efficacy studies, including follow-up of up to 5 years of vaccinated individuals.

The vaccine does not cease to be safe when a signal is detected. It is an alert that needs to be investigated more thoroughly. This identification after application is part of the process and is being analyzed with the utmost rigor.

Therefore, continuous monitoring is essential, and it works.

Are those who have already received the vaccine at risk?

Those who have received the vaccine are protected against the four types of dengue: the decision does not invalidate the vaccine's effectiveness. Vaccines, like any other medications, are not exempt from rare and unexpected events. The identified risk is rare. More than 90% of vaccinated individuals did not experience side effects after vaccination. The vast majority of reported effects are mild to moderate, disappearing after a few days.

The recommendation remains the same for those who have been vaccinated: monitor your health for up to 21 days after the dose. Seek immediate medical attention if you experience fever, severe abdominal pain, persistent vomiting, bleeding, dizziness, excessive drowsiness, signs of dehydration, or a worsening of your general condition.

After 21 days, no active component of the vaccine is detectable in the body.

What are the most common adverse effects?

According to the vaccine leaflet, the expected adverse effects in some vaccinated individuals are: headache, body aches, eye pain, skin rashes, extreme fatigue, itching, nausea, sensitivity to light, and chills.

Very rarely, cases similar to dengue fever with fever have been detected.

Does this mean the vaccination strategy failed?

No. On the contrary. The identification of cases shows that the vaccine monitoring and safety mechanisms work and can quickly detect possible warning signs.

Was there a problem with the storage or application of the vaccine?

There is no evidence of failures in the storage, transport, or application of the doses. These hypotheses continue to be verified during the investigations.

What will be done with the doses that are already in the health centers?

The vaccines should not be discarded or destroyed. They should remain stored in the cold chain until the investigation is completed.

Are vaccines still important?

Yes. Vaccines remain one of the main tools for preventing diseases and saving lives. The investigation of a possible rare and unexpected adverse event demonstrates that the surveillance system is working.

According to the WHO, vaccines have saved 154 million lives in the last 50 years, about 3 million per year. In Brazil, vaccines have helped eradicate polio (infantile paralysis) and rubella, and in the case of measles, the country is free of the disease.

When will there be a decision on resuming vaccination?

The decision will depend on the results of ongoing investigations. The Ministry of Health and Anvisa will release new guidelines as soon as there are sufficient technical conclusions. Anvisa will have a panel of experts to further investigate the epidemiological situation regarding this vaccine.

What is the current dengue scenario in Brazil in 2026?

This year, up to May 30th (week 21), Brazil registered a 97% reduction in deaths and a 94% reduction in probable cases compared to the same period in 2024.

However, dengue fever remains the country's most endemic disease. Vaccines continue to be fundamental weapons in this fight and will help achieve even better results.

Ministry of Health