Answer your questions about the dengue vaccine

The Qdenga vaccine, from the Japanese laboratory Takeda, will begin to be distributed next week to 521 municipalities selected by the Ministry of Health. The vaccine had been approved by Anvisa (National Health Surveillance Agency) in March 2023. In December, the government announced the incorporation of the input into the SUS (Unified Health System).

The cities that will receive the vaccine are considered endemic for the disease. Children and adolescents aged 10 to 14 will be immunized, one of the age groups that has the highest number of hospitalizations for dengue, second only to the elderly.

Read below some of the main questions and answers about vaccination with Qdenga in the country:

• When does vaccination against dengue begin in the SUS?

The forecast is that the doses will begin to be distributed to the 521 municipalities next week. According to the Ministry of Health, cities are free to start vaccination as soon as doses begin to arrive. The organization of campaigns, including dates, times and vaccination points, will therefore be the responsibility of state and municipal governments. It will be necessary to check the schedule with city halls and state and municipal health departments.

• Who can get the vaccine through SUS?

Although the Qdenga leaflet indicates the immunizer for people aged 4 to 60 years, the ministry announced that, in the SUS, in principle, the target audience will only be children and adolescents aged 10 to 14, one of the groups that concentrates highest number of hospitalizations due to dengue, second only to the elderly. The decision was made due to the limited quantity of doses provided by the manufacturing laboratory.

• I am not among the priority audience. How do I get the vaccine?

Anyone outside the age group classified as priority can seek the vaccine in the private network. In this case, you need to be careful, as there are 2 different immunizers on the market: Qdenga and Dengvaxia, from the French laboratory Sanofi. The 2nd option is recommended for people aged 6 to 45 who have already had dengue fever.

• What is the price of the vaccine in the private system?

The price charged in private laboratories and pharmacies has fluctuated a lot over the last 11 months. Those who took the dose as soon as Qdenga was approved by Anvisa paid cheaper. Today, prices are around R$400 per dose, with the combo with two doses (complete scheme) being cheaper.

• Can pregnant and breastfeeding women get the vaccine?

Qdenga is contraindicated for pregnant and breastfeeding women and, therefore, cannot be administered either in the public or private network. The dose is also not recommended for people with primary or acquired immunodeficiencies and individuals who had a hypersensitivity reaction to the previous dose. Women of childbearing age who intend to become pregnant must use contraceptive methods for a period of 30 days after vaccination.

• Why is the vaccine not recommended for people over 60?

People over 60 years of age are not recommended to receive the dose due to the lack of clinical studies. Despite this, the EMA (European Medicines Agency) and Anmat (Administración Nacional de Medicamentos, Alimentos y Tecnología Médica), an Argentine regulatory agency, approved the use of Qdenga from 4 years of age with no upper age limit. , considering potential benefits in the group, more susceptible to severe forms of the disease.

“Therefore, the recommendation for individuals over 60 years of age should be seen as an off-label indication, at medical discretion, supported by approval by other regulatory agencies, but without data certifying safety and efficacy.”, explained SBim (Brazilian Society of Immunizations).

• Does the vaccine also protect against Zika and Chikungunya?

Qdenga exclusively prevents cases of dengue and does not protect against other types of arboviruses, such as zika, chikungunya and yellow fever. For yellow fever, two vaccines are available: one produced by Fiocruz (Fundação Oswaldo Cruz), used by the public network, and another produced by Sanofi, used by private immunization services and, eventually, by the public network.

• How many doses and what are the vaccine application intervals?

The complete Qdenga regimen consists of two doses, to be administered subcutaneously with an interval of 3 months between them. Anyone who has had dengue fever should also take the doses. The recommendation, in these cases, is especially indicated due to the better immune response to the vaccine and because it is a population classified as being at higher risk for severe cases of the disease.

For those who have recently had the infection, the recommendation is to wait 6 months to receive the vaccine. Anyone diagnosed with the disease in the interval between the two doses must maintain the vaccination schedule, as long as the period is not less than 30 days from the onset of symptoms.

• Has the dengue vaccine been tested?

Qdenga proved to be effective against type 1 dengue in 69.8% of cases; against type 2 dengue, in 95.1%; and against type 3 dengue, in 48.9%. Efficacy against type 4 dengue fever could not be assessed due to the insufficient number of cases caused by the serotype during the study. There was also efficacy against hospitalizations due to dengue, with overall protection of 84.1%, in addition to similar estimates between seropositive (85.9%) and seronegative (79.3%).

• How many and what are the dengue vaccines approved for use in Brazil?

Qdenga is the first dengue vaccine approved in Brazil for a wider audience, as the previously approved vaccine, Dengvaxia, can only be used by those who have already had the disease. Dengvaxia was not incorporated into the SUS and is contraindicated for individuals who have never had contact with the dengue virus due to the risk of developing severe cases of the disease.

• Are there studies for the production of a Brazilian vaccine against dengue?

The Butantan Institute, which is the largest producer of vaccines and serums in Latin America and the main producer of immunobiologicals in Brazil, is in the final phase of developing a new vaccine against dengue. Like Qdenga, the Butantan vaccine is tetravalent and, therefore, protects against the 4 subtypes of the virus, but has a difference: it will be administered in a single dose, against the two necessary doses of Qdenga. The institute is expected to file a registration request with Anvisa this year.

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With information from Brazil Agency.