Data from a phase 3 study SHOW that a vaccine against dengue developed by the Butantan Institute was 79% effective in preventing the disease after two years of application. During the analysis, no serious cases of infection were recorded in the participants.
The information is still preliminary – the five-year follow-up from vaccination still needs to be completed, which should only happen in 2024.
Only after that, the institute will submit the drug for analysis by Anvisa (National Health Surveillance Agency), which is responsible for approving or not the immunizer.
The vaccine is a single dose and uses four attenuated viral strains in its composition. Called Butantan-DV, it is an analogous version of the one developed by the US National Institute of Health. Pharmaceutical MSD is also part of the immunizer development project.
The research that evaluates the vaccine’s efficacy data began in 2016. In total, there were more than 16,000 volunteers aged between 2 and 59 years old in the survey, with about 10,000 receiving the immunizer and the rest making up the placebo group .
Among all participants, some had already been infected with the virus that causes dengue and is transmitted by mosquitoes. aedes aegypti🇧🇷 Still others were unscathed by the disease.
With this division, Butantan was able to measure the general effectiveness of 79% of the vaccine, but also the differences seen in the two groups. In those with a history of dengue, efficacy was around 89%. For the other portion of participants without a record of the disease, the protection conferred by the vaccine was lower —73%.
Another peculiarity observed in the research was for the serotypes of the virus. The vaccine is produced by four strains of the pathogen, called DENV-1, DENV-2, DENV-3 and DENV-4.
According to Butantan, serotypes 3 and 4 did not circulate widely in Brazil during the analysis period. Therefore, it was not possible to conclude the effectiveness of the vaccine specifically for the two strains.
In the case of DENV-1 and DENV-2, the survey concluded that the vaccine had an overall effectiveness of 89% for the first and 69% for the second.
In addition to efficacy information, immunizer safety was also measured. Butantan observed that, in the group of volunteers who were immunized, less than 0.1% had reports of serious adverse events related to the vaccine.
situation in Brazil
According to data from the Ministry of Health, dengue has already caused more than 1,400,100 probable cases in Brazil up to December 3 of this year. The number represents an increase of 172% compared to last year’s information. Compared to 2019, the pre-pandemic year, there was a reduction in cases of 7.7%.
In total, there were 1,414 records of serious cases this year, with 978 deaths.
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