Dengue fever is a mosquito-borne disease caused by four dengue virus serotypes (1 to 4). Overall, the disease is a potential threat to almost half of the world’s population. Of the estimated 100 million people infected annually, 500,000—mostly children—develop dengue hemorrhagic fever (DHF), a severe form of the disease. DHF is a leading cause of hospitalization, placing tremendous  pressure onstrained medical resources and having a heavy economic and societal impact.
 
Many factors have contributed to the re-emergence and dramatic increase in dengue fever including urbanization and increased travel which facilitates dissemination of dengue viruses and the circulation of all four dengue virus serotypes. Sanofi Pasteur, a world leader in vaccines, has taken on the challenge of providing the first dengue vaccine for individuals living in endemic areas as well as for those who plan to travel to those areas.