Dengue vaccine should be available in Brazil until 2016

Publicação: 11 de September de 2014

Research showed a reduction of 88.5% of the severe cases in Asian countries and global efficiency aligned to the goal of dengue mortality established by the WHO

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With the data, the dose’s entry in the market relies only on the federal government

The efficiency studies of a vaccine against dengue fever tested in Latin American are to be released in September. The announcement was made by the CEO of Sanofi Pasteur Brasil, Hubert Guarino during the 50th Congress of the Brazilian Society of Tropical Medicine (MEDTROP), that took place from August 26 to 29 in Rio Branco, Acre. According to him, with the data in hands, the vaccine’s commercialization relies only on the federal government and could happen already in 2016.

“Projecting a positive scenario for the results as well as the accelerated process of the do dossier, we can imagine the Brazilian population being benefitted by a protection to dengue’s seasonality by the end of 2016, once until the end of that year, people will have received two doses of the vaccine”, informed Guarino. The target audience and recommended ages for the product will be defined after the conclusion of the clinical studies.

The company assures to be able to produce 100 million annual doses and ship them from 2015’s second semester to the countries that already authorized the use and commercialization of the product. In Brazil, the analysis will be conducted by the National Sanitary Surveillance Agency (ANVISA). A possible purchase of the vaccines by the Health Ministry will depend on the Brazilian government’s strategy – in 2014, R$ 1.2 billion (over USD 500 million) should be invested in the disease’s combat.

This is a chimerical live vaccine, in which the proteins from the pre-membrane and the envelope of four serotypes of the virus are expressed through the replacement of the attenuated yellow fever virus’ genes. More information can be accessed in  in English or in in Portuguese. According to the PhD in Health and Investigative Medicine Biotechnology, Guilherme Ribeiro, the product still needs enhancements, but is already a great accomplishment. “They (Sanofi) demonstrated the product has an efficiency over 60%. It is not perfect, but carries a potential benefit as complementary measure to the control and prevention actions from the federal government. It is an impact addition to reduce the disease’s incidence. I think there is space for enhancements and vaccine development, but without a doubt it is safe”, explained the BSTM’s member.

Data from the World Health Organization (WHO) suggest that every year 100 million people are struck by dengue fever. Last year, Brazil registered nearly 1.5 million cases, from which 6.5 thousand were the disease’s severe form and 573 deaths. A vaccine against this disease would represent an important advance in controlling the disease, and could be an important tool to meet the WHO’s objectives to reduce dengue mortality at least in 50% and morbidity in at least 25% until 2020.

Analysis in Asia and Latin America

In Latin America the study should be released still in September. At all, 20 thousand volunteers from Colombia, Mexico, Puerto Rico, Honduras and Brazil participated. Here, the studies took place in Campo Grande (MS), Goiania (GO), Fortaleza (CE), Natal (RN) and Vitoria (ES). According to Sanofi Pasteur’s Medical Manager the vaccines were tested in over 3.5 thousand healthy children from 9 to 16 years of age between 2011 and 2013. “The idea was to evaluate the vaccine’s efficiency in this dengue susceptible population. The study was made in a proportion of 2 to 1, this is, for every two immunized children, one child received the placebo dose to compose the comparative analysis”, he explained.

In September, Sanofi Pasteur announced the vaccine’s global results were able to reduce in 60.8% the total of disease cases. Additional observations also showed a decrease of 80.3% of the hospitalization risk due to dengue in the period. The research’s detailed data will be made available in a scientific journal and should be announced in November, during the annual meeting of the American Society of Tropical Medicine and Hygiene (ASTMH), in the USA.

The research to produce this vaccine started 20 years ago and had the results from five asian countries published in July’s Lancet. The phase 3 of the clinical study, the last  step to test the drug’s efficiency showed a decrease of 56.5% of the symptomatic dengue cases and 88.5% of the haemorrhagic and severest form of the disease. Over 10 thousand children from 2 to 14 years old who live in endemic areas for dengue joined the analysis between 2011 and 2013, receiving three vaccine doses during the period.

Advances of another study on the disease

A research  by scientist in the USA and in Singapore revealed a new pathway the dengue fever virus runs to suppress the human immune system. According to the study, when a virus enters the body and infects cells, it induces the production and release of interferons (IFNs), which are proteins that raise the bodies’ anti-viral defense mechanisms. The neutralization of this defense mechanism can be another step closer to new solutions against the disease. In a short interview to the Brazilian Society of Tropical Medicine (BSTM), the chair of the Medicine Center from Duke University (USA), Dr. Mariano Garcia-Blanco  explains what he expects from the actions against the disease, as the announcement of the release of a vaccine – the dialog below took place during the announcement of the Sanofi Pasteur’s product – and about his team’s studies.

BSTM: Is there a forecast of when a vaccine against dengue fever will be available in the market?

M. G-B: I don’t trust any of the forecasts, but I would risk saying it could be 10 years before it comes to the market shelves – I hope I am wrong.

BSTM: Will such vaccine be accessible to the poorest countries or should it be expensive at first?

M. G-B: I belive yes, in case countries with more resources as Brazil or Singapore form alliances with poor developing countries, as well as the USA and the European Union, to assure the vaccine will be distributed. An example of having a great vaccine and not distributing it well is the yellow fever vaccine – a fantastic vaccine available since the 30s, and many people worldwide still die from the disease.

BSTM: What is the goal of the research and which are the expected results?

M.G-B: My research is trying to understand how the flavivirus replicates (mechanically) and use this knowledge to develop antiviral compounds that may serve to treat diseases caused by them. Specifically, we are interested in the role of host factors (very specifically from those, which’s proteins react with viral RNAs that help or prevent viral replication.

BSTM: In which countries are these vaccine tests being conducted and which are the current results?

M.G-B: My studies (which are not clinical) are conducted in the USA and in Singapore.…