West Nile virus vaccines in trials

Three vaccines targeting West Nile virus, a type of viral encephalitis spread by mosquitoes, are in National Institutes of Health (U.S.) clinical trials. The vaccines, already tested in animals, are being tested for safety in humans. In 2004, 2,470 cases of West Nile virus illness were reported in the United States, and 88 of those infected died. Vaccination of individuals at risk for serious complications, such as the elderly or those with weakened immune systems, could reduce deaths from the disease. One of the studies which began on March 22, 2005, is seeking volunteers.