Portugal already has a dengue vaccine that does not require pre-exposure

Since last week, Portugal has had a dengue fever vaccine that does not require prior exposure to the virus, is effective against the disease, and prevents hospitalization for four and a half years after vaccination.

As director of the Institute of Hygiene and Tropical Medicine (IHMT) Filomeno Fortes explained to Luce, for those who have not yet had contact with the virus and traveled to areas endemic for the disease, the only guidance was the use of repellents and long-sleeved clothing to prevent mosquito bites. The available vaccine could only be administered to those who had already been exposed to the virus.

Highlighting that dengue fever is one of the top 10 global public health threats according to the World Health Organization (WHO) and occurs in more than 125 countries, Filomeno Fortes stressed the importance of the new vaccine approved in December by Infarmed.

“It is already indicated for people who have or have not had an infection, between the ages of four and 60,” he explained, adding that it should be taken in two doses one to three months apart.

Asked about the possibility of reimbursement by the National Health Service (SNS), he says that it would make sense for the authorities to consider this hypothesis “if there were outbreaks, as has already happened in Madeira.”

“Assuming that here in Portugal, in Madeira, where we have Aedes aegypti, where there have been dengue epidemics in the past, if we are faced with a situation of risk of a re-emergence of the epidemic, the authorities should decide whether they intend to massively vaccinate the population. population, in which case the SNA should bear the costs,” he said.

And he explains the advantage of vaccinating the entire population of a certain area where outbreaks occur: “When a mosquito bites a person, it introduces the virus into the blood. [se a pessoa estiver vacinada] prevent a mosquito from affecting this organism, but this person, while he is infected, (…) if bitten, he can infect another mosquito, which in turn can transmit the virus to other people. the mosquito, once infected, is always infected, and that the eggs it leaves behind when they hatch “hatch already with infected vectors”.

The new vaccine, which protects against all types of dengue fever, is “80% effective after 12 months,” he said, and is 90.4% effective in preventing hospitalizations. Filomeno Fortes also adds that this new vaccine is “fully effective” against dengue variant 2: “With two doses, there is zero chance of developing even mild symptoms.”

As for the other serotypes (1, 3 and 4), those vaccinated may develop “very mild disease”. From a public health perspective, he insists on the need to increase disease literacy, reminding both the public and healthcare workers that symptoms can initially be confused with those of the flu.

Maintaining surveillance and vector control measures is another priority, especially where Aedes albopictus (on the Portuguese mainland) and Aedes aegypti (on Madeira) mosquitoes have already been detected, as well as ongoing epidemiological surveillance. He also points to the need to have “diagnostic capacity”, noting that there is a rapid test that any doctor can use to rule out infection and that it should be available at health centers.

If there is a confirmed case of dengue fever – warning – certain types of medication should be avoided “because they may interfere with the patient’s bleeding.”

He explained that IHMT recommends travelers traveling to areas where dengue is endemic to get vaccinated at least two weeks in advance.