The Ebola virus causes a hemorrhagic fever that progresses rapidly and that has high mortality rates. An experimental vaccine involving a combination of DNA immunization and boosting with adenoviral vectors (ADV) against the most lethal subtype (Zaire) of Ebola virus exists. However, this vaccine requires more than 6 months to achieve complete immunization, rendering it impotent in limiting an acute epidemic. In the August 7 Nature, Nancy J. Sullivan and colleagues at the National Institutes of Health show that a single vaccine injection with ADV vectors encoding viral proteins can be an effective accelerated vaccination strategy against Ebola virus in monkeys (Nature, 424:681-684, August 7, 2003).