Sanofi’s Dengue Vaccine Made Widely Available for First Time
Source: Mikael Haggstrom (Wikipedia)
The Philippines plans to immunize schoolchildren starting in April 2016, as Sanofi Pasteur, the vaccines division of France’s Sanofi SA, made the Philippines the first country where its 1) ___ for dengue fever will be widely available. Conchita Santos, manager for Sanofi Pasteur in the Philippines, said the company’s facility in France is expected to produce 100 million doses of the vaccine a year when it is fully operational to cover global needs.
Dengue has become the most rapidly expanding 2) ___-borne infectious disease on the planet, surpassing malaria and infecting at least 390 million people per year. The mayor of Hawaii’s Big Island declared a state of emergency to deal with a growing outbreak of dengue fever, spread by infected mosquitoes, with 250 cases confirmed over the past four months, making it the largest outbreak in Hawaii since the 1940s, according to Hawaii health officials, and the largest 3) ___ in the United States.
Dengue fever causes flu-like symptoms and can develop into the deadly dengue hemorrhagic fever. There is no effective treatment for dengue illness other than supportive care, especially for severe cases. Symptoms can be mild or life-threatening as in dengue hemorrhagic fever and dengue shock syndrome. Vector control has been only partially successful in decreasing dengue transmission. The potential use of safe and effective tetravalent dengue vaccines is an attractive addition to prevent disease or minimize the possibility of 4) ___. Currently five candidate vaccines are in human clinical trials. One has completed two Phase III trials, two are in Phase II trials, and three are in Phase I testing.
Dengue virus (DENV) is a mosquito-borne flavivirus that infects at least 390 million people per year. It is estimated that nearly half the world’s population is at risk for dengue infection. A recent report from the Pan American Health Organization points out that reported dengue cases in the Americas rose by a factor of five in the last ten years. The primary mosquito vector for dengue, Aedes aegypti, continues to spread widely and into new habitats due to increased urbanization as well as 5) ___ change. The less efficient vector A. albopictus is also rapidly expanding its habitat, as temperatures climb and flooding continues. Dengue has become the most rapidly expanding mosquito-borne infectious disease on the planet, surpassing 6) ___. Dengue infection and illness are caused by four distinct DENV serotypes that cross-react immunologically. Because of the magnitude of the dengue problem worldwide, more than one of these vaccine candidates will be needed to ensure an adequate vaccine 7) ___ in the long run.
As of this date, only the Sanofi CYD vaccine has made it through phase III trials. This vaccine has been shown to be safe and has different levels of efficacy against the four serotypes, with highest efficacy against serotypes 3 and 4. In addition, it has been shown to have very high efficacy against severe clinical disease and hospitalization due to dengue. This vaccine has also been shown to work better in people with some prior dengue 8) ___, and to be less efficacious in those with no prior dengue immunity. Mathematical modeling has shown that a vaccine with suitable characteristics could be quite effective in reducing overall dengue illness levels in populations that receive such a vaccine over time by routine vaccination of 9) ___ with a single catch-up campaign in older children and possibly adults. Much more work needs to be done to determine how dengue vaccines, once licensed, could be deployed, but it is clear that dengue vaccines will soon join vector control as a means for dengue control.
Johns Hopkins has a contract with 10) ___ to study vaccines, including dengue vaccines that are developed by the NIH. Other pharmaceutical companies in clinical trials with dengue vaccines are Takeda, Merck, GSK with Walter Reed Army Institute of Research.
ANSWERS: 1) vaccine; 2) mosquito; 3) outbreak; 4) epidemics; 5) climate; 6) malaria; 7) supply; 8) immunity; 9) children; 10) NIH