Dengue fever vaccine shows promise after clinical trials

MADISON, WIS. — A new vaccine to protect against dengue fever has proven safe and effective in preclinical studies involving nonhuman primates, scientists recently reported in the American Journal of Tropical Medicine and Hygiene.

In 2006, InViragen, based in Fort Collins, Colo., received a multi-million dollar grant from the National Institutes of Health (NIH) to help develop a dengue fever vaccine. The four-year grant funded a collaborative effort led by Dan Stinchcomb, InViragen's chief executive officer, and involved scientists at the Division of Vector-Borne Infectious Diseases at the Centers for Disease Control and Prevention (CDC) and the University of Wisconsin-Madison's (UW-Madison) veterinary school.

Dr. Jorge Osorio, assistant professor in the Department of Pathobiological Sciences at UW-Madison's veterinary school is the lead author on the paper and is also InViragen's chief scientific officer.

The Wisconsin National Primate Research Center's Animal Services Division helped acquire the cynomolgus macaques used for the study and performed much of the technical work, according to Division Associate Director Saverio Capuano.

The InViragen vaccine combination proved safe, induced neutralizing antibodies to all four dengue serotypes, and protected the monkeys against dengue infection, according to the authors.

The four dengue viruses, spread by mosquitoes, cause an estimated 0.5 to 2 million cases of life-threatening dengue hemorrhagic fever every year, UW-Madison reports.

"Recent dengue fever outbreaks in India, Pakistan and Cuba have emphasized the need for this vaccine," Stinchcomb says. A dengue outbreak in Florida highlights the continuing global spread of the disease. Dengue fever is already a major public-health problem in Southeast Asia, the Pacific Islands, the Caribbean, Mexico, Central and South America and parts of Africa.

If successful in human clinical trials, InViragen's dengue vaccine may be used to protect children and adults in these endemic countries and to protect travelers to those regions, the university says.