President Donald Trump has been cranking up the pressure on his health officials to hurry up with their coronavirus vaccine so he can declare victory over the pandemic before he faces re-election. On Thursday night, he told a Pennsylvania rally that the vaccine “really might even be delivered before the end of October... How do you like that?” But Trump’s confidence apparently is not shared by the chief adviser for the White House vaccine program. Moncef Slaoui told NPR Thursday that it was “extremely unlikely but not impossible” that a vaccine could be available by Halloween. He said that it was right for the Centers for Disease Control and Prevention to prepare states to roll out a vaccine as early as October, but said there’s a “very, very low chance” that the rushed timeline will actually come to pass. However, Slaoui did add a note of optimism, saying: “I firmly believe that we will have a vaccine available before the end of the year.”