Pharmaceutical company AstraZeneca said Tuesday it had "voluntarily paused" a randomized clinical trial of its coronavirus vaccine in what it called a routine action after a volunteer developed an unexplained illness. The company, which is developing the drug alongside the University of Oxford, is a frontrunner in the global race for a Covid-19 vaccine. "As part of the ongoing randomized, controlled global trials of the Oxford coronavirus vaccine, our standard review process was triggered and we voluntarily paused vaccination to allow review of safety data by an independent committee," a spokesperson said.