Coronavirus Live Updates: Moderna and N.I.H. Begin Vaccine Trial
Here’s what you need to know: ImageRobert O’Brien, the national security adviser, on the South Lawn in March. He is the most senior White House official known to have contracted the coronavirus.Credit…Al Drago for The New York Times Trump’s national security adviser, Robert O’Brien, tested positive for the virus. President Trump’s national security adviser, Robert C.…