Science's reporting offers insight into some strategies companies may use. GlaxoSmithKline, a Belgium-based pharmaceutical company that's working on what's now the world's most advanced Ebola vaccine, has proposed using speedier quality-control tests. The company also plans to run two trials of its vaccines at once. The two trials will take place in different countries—Liberia and Sierra Leone—and will have different structures—the Liberia trial is more classically designed, with some study volunteers taking a placebo, while the Sierra Leone trial has a "stepped-up wedge" design that involves giving everybody the experimental shot, just at different times. It's a case of hedging their bets. "One of the trials may fail for logistics reasons," the head of GlaxoSmithKline's Ebola vaccine effort, Ripley Ballou, told Science. "We only have one shot to get this right.