US President Donald Trump said that a coronavirus vaccine may be available within a month – an acceleration of even his own optimistic predictions – but added that the pandemic could go away by itself.“We’re very close to having a vaccine,” he told a town hall question and answer session with voters in Pennsylvania aired on ABC News on Tuesday.“We’re within weeks of getting it you know – could be three weeks, four weeks,” he said.Only hours earlier, speaking to Fox News, Trump had said a…