Xcellerex, Inc. has initiated a Phase I trial of XRX-001, a prophylactic vaccine against yellow fever, a tropical virus disease that is often fatal. The vaccine is being developed to prevent yellow fever in people traveling to tropical countries where yellow fever is prevalent. The currently available yellow fever vaccine is an attenuated, live vaccine with rare but potentially serious adverse effects. XRX-001 is an inactivated virus vaccine adsorbed to alum adjuvant, which is expected to sig...