President Joe Biden said that the United States is facing a “national emergency” in the coronavirus pandemic and his administration is working to supply enough COVID-19 vaccine to inoculate 300 million Americans. “We’re in a national emergency,” said Biden, wearing a mask during remarks to scientists at the National Institutes of Health just outside Washington, DC on Thursday. “This will be one of the most difficult operational challenges we have ever undertaken as a nation. It’s going to take time,” Biden said. He also used this opportunity to attack President Trump. Biden said the coronavirus vaccination program he inherited from...