Fifteen months after the global pandemic officially began, it's still unclear how it originated – and a group of top American scientists is eager for answers. In a letter in the current issue of the journal Science, 18 infectious disease experts, immunologists and epidemiologists joined a global call for more information about the earliest days of the outbreak. There still isn't enough known, they said, to determine whether the coronavirus jumped directly from animals to people or whether it was released from a research laboratory in China. The lack of information, they said, feeds conspiracy theories and prevents scientists and policymakers from taking steps to prevent the next deadly pandemic.