WASHINGTON, D.C.--September 11, 2012--Today, The Dengue Vaccine Initiative (DVI) welcomed new clinical trial results that reveal progress in developing the first-ever dengue vaccine. In a publication in The Lancet, pharmaceutical company Sanofi Pasteur reported results from the first study conducted to evaluate the efficacy of any dengue vaccine candidate against clinical dengue disease in a population naturally exposed to dengue.
Dengue vaccine development efforts have been difficult because dengue is caused by four different related viruses, known as DENV 1, 2, 3 and 4. The results published in today's study found that Sanofi's vaccine candidate was effective against DENV 1, 3 and 4, but DENV 2 appeared to be resistant to vaccine in this trial. The vaccine candidate, called CYD-TDV, was tested on a group of 4,002 schoolchildren in Thailand, where dengue is known to be endemic.
"While there is still much work to be done, these clinical trials mark a decisive step forward in the development of a safe and effective vaccine," said Dr. Luiz da Silva, Director of the Dengue Vaccine Initiative. "We support the progress made by Sanofi Pasteur as well as efforts by other organizations to deliver a vaccine to populations in endemic countries."
There is no vaccine available to treat or prevent dengue fever. While vaccines have been under development since the 1940s, little progress had been made until recently. Reported dengue cases have increased from an annual average of fewer than 300,000 cases during the 1980s to nearly 1 million per annum from 2000 to 2005.The WHO estimates that there are 50 to 100 million dengue infections a year.
"This is a dramatic increase in dengue incidence rates, and yet it's very likely that the numbers still do not reflect the full scope of the problem," said Dr. Ciro de Quadros, Executive Vice President of the Sabin Vaccine Institute. "An exact number is difficult to determine due to a lack of accurate diagnostic testing and common misdiagnosis."
Dengue is the most common mosquito-borne viral disease, with more than 2.5 billion people at risk for the disease globally, resulting in an estimated 21,000 deaths per year. Dengue symptoms can range from mild, flu-like symptoms to severe circulatory failure, coma and death. Most outbreaks occur during the rainy season in endemic countries like Thailand and Brazil, when mosquito populations are high.
Currently, there are several dengue vaccines in various stages of development, with four candidates, including Sanofi Pasteur's, in clinical trial stages. The results of this first study, a phase IIb clinical trial, are not yet sufficient to prove or disprove efficacy of CYD-TDV. However, Sanofi has already begun phase III studies among 31,000 children in Asia and Latin America. These studies will provide further information, including pivotal efficacy results and additional safety data.
"In addition to saving lives and reducing illness, a dengue fever vaccine, once introduced, will have significant positive impacts on the global economy," added Dr. Orin Levine, Executive Director of the International Vaccine Access Center at the Johns Hopkins Bloomberg School of Public Health. "The cost of dengue fever in the Americas alone is estimated to be $2.1 billion annually, and the burden of lost wages and productivity, along with the cost of healthcare, takes a great toll in endemic countries across the globe."
DVI is working to lay the groundwork for dengue vaccine introduction in endemic areas so that, once licensed, vaccines to prevent dengue will be swiftly adopted by countries most in need. The DVI consortium, which includes the Sabin Vaccine Institute, the International Vaccine Institute (IVI), the World Health Organization (WHO) and the International Vaccine Access Center (IVAC), builds on the momentum and capabilities of the Pediatric Dengue Vaccine Initiative (PDVI) and focuses on creating an enabling environment for vaccine introduction and on maintaining a pipeline of vaccine candidates.
DVI's advocacy and communications activities are managed by the Sabin Vaccine Institute, a non-profit global health advocacy and resource mobilization organization based in Washington, D.C.
About the Dengue Vaccine Initiative
The Dengue Vaccine Initiative (DVI) was established in 2010 to build on the work of the Pediatric Dengue Vaccine Initiative and to further awareness of the need to support the development and use of dengue vaccines. The goal of the DVI is to accelerate the introduction of safe and broadly protective vaccines into the national immunization programs of endemic and developing countries. DVI works with scientists, vaccine experts and policymakers from concept to implementation, promoting the development of dengue vaccines while also advocating with governments worldwide to ensure the swift adoption and distribution of a vaccine to those most in need. To learn more visit www.denguevaccines.org.
About Sabin Vaccine Institute
Sabin Vaccine Institute is a non-profit, 501(c)(3) organization of scientists, researchers and advocates dedicated to reducing needless human suffering from infectious and neglected tropical diseases through prevention and treatment. Sabin works with governments, academic institutions, scientists, medical professionals and other non-profit organizations to provide short and long-term solutions for some of the globe's toughest health care challenges. Since its founding in 1993 in honor of the oral polio vaccine developer, Dr. Albert B. Sabin, the Institute has been at the forefront of global efforts to eliminate, prevent and cure infectious and neglected tropical diseases by developing new vaccines, establishing international networks, and advocating for effective and efficient delivery of preventions and treatments to the world's poor. www.sabin.org