An article in Science Magazine describes a remarkable Ebola vaccine trial conducted by a team for the World Health Organization (WHO). The researchers' approach was partly dictated by an unexpected decrease in the number of Ebola cases, nullifying traditional vaccine research involving thousands of participants. The Guinea consortium opted for an unusual "ring" vaccination design, in which only the people most at risk — those who came into contact with an Ebola infected person and the contacts' contacts — were enrolled. The trial yielded a finding of 100% statistical efficacy for the vaccine, inspiring praise from epidemiologist Michael Osterholm, director of Consortium member the Center for Infectious Disease Research and Policy (CIDRAP). “We will teach about this in public health schools,” notes Osterholm.