Each of the Ebola vaccines being lined up for testing carries potential downsides, researchers say, ranging from efficacy that faded in less than a year to the chance it will give healthy people flu-like symptoms. Human trials, just starting on some vaccines, could also unveil unknown side effects, an unwelcome possibility for shots designed to be taken by people who may never be infected with Ebola. Because of this, it is imperative we cast a wide net in seeking a solution. Currently, safety testing has begun on vaccines from GlaxoSmithKline Plc and NewLink Genetics Corp. Trials for three other vaccines will begin later next year, but although they show some signs of effectiveness in animals does not mean they will work on humans, said Thomas Geisbert, a virologist at UTMB.