Starting in February, the Unified Health System (SUS) will offer the vaccine that protects against dengue, known as Qdenga. According to the Ministry of Health, Brazil will be the first country in the world to implement dengue vaccination through the public health system. 5.082 million doses will be delivered in 2024, between February and November. Initially, vaccination will focus on general areas and priority areas. About 3.1 million people will be immunized with Qdenga.
According to the folder, the Qdenga vaccine (TAK-003) was developed by the Japanese Takeda Pharma laboratory. The vaccine was approved for registration by the National Health Surveillance Agency (Anvisa) in March 2023. The vaccine is recommended for people aged 4 to 60 years and must be given in two doses, three months apart. Everyone, even those who have already had dengue fever, will be able to receive the vaccine.
How does the vaccine work?
According to infectious diseases doctor Fernando Chagas, the dengue vaccine consists of an attenuated virus, that is, a live virus, but weakened and containing fragments of the other three types of dengue fever spread around the world.
“We have 4 types of dengue that we classify as DENV 1, DENV 2, DENV 3 and DENV 4. The vaccine is a DENV 2 virus, but with parts of the other types 1, 3 and 4 that were once present in the body. It stimulates antibody production and cellular defense. Against the four types of dengue fever. In studies, it has shown an average effectiveness of 80% in reducing cases and for people who have had the disease, more than 90% at risk of progressing to a severe form. So it is very effective, he explains.
The infectious disease specialist highlights that in studies and in populations that received the vaccine, adverse effects were very mild, generally within two days after application.
“We've generally noticed signs and symptoms that resemble even febrile illnesses, such as low-grade fever, sometimes a little muscle pain, and it's usually mild. Some people have reported a mild headache that lasts for one to three days on average,” he says. A sign or symptom that lasts more than 3 days means that a person should consider the possibility of contracting the disease at the same time as receiving the vaccine or even before receiving the vaccine, so it is important to seek medical care.”
Since it is a vaccine consisting of an attenuated virus, it will not be possible to give Qdenga to certain groups, the infectious disease specialist explained.
“People with diseases that weaken the immune system or who use medicines that suppress the immune system, for example, people who use corticosteroids for more than 15 days. Also, pregnant and breastfeeding women will not be able to receive the vaccine because there is slight damage to their immunity and we do not know the effects of the vaccine on pregnant women and because there are no studies on the transmission of the disease, he says: the virus or the milk vaccine.
For Chagas, the dengue vaccine is a strategy that could help strategies to combat the disease virus – halting not only the increase in the number of cases, but also the number of deaths.
“We do not have specific medicines against the dengue virus. Therefore, the measures we took were always aimed at controlling the vector of infection, which is the Aedes aegypti mosquito. Fighting an insect with such great adaptability becomes very difficult. That is why we always end up losing this The battle. But the vaccine ultimately comes with a strategy that's targeted directly against the virus, which, in addition to the strategy that we already have against the mosquito vector, will likely have a very positive impact, which is a very significant reduction not only in new cases, but also deaths. Caused by dengue fever across the country in the coming years.
Source: Brazil 61
