The "GlaxoSmithKline-backed team that described an acceptable immune response after two adjuvanted 3.8-microgram (mcg) doses found that three fourths of their subjects were protected not only against the clade 1 Vietnam virus on which the vaccine was based, but against a drifted clade 2 virus from Indonesia as well [...] To achieve prepandemic vaccines, researchers would have to ascertain the right dose and dose interval, determine how long priming lasts, and solve the puzzle of measuring primed immunity. Further, regulatory authorities would have to determine the trial design that could deliver those answers, the public discussion that would be necessary for prepandemic vaccines to be accepted, and the safety data that would need to be gathered once the vaccines went into use".