Dr. Anthony Fauci, the nation's top infectious disease expert said the United States is in "a very, very difficult situation" with COVID-19, after experiencing 10 million infections and more than 240,000 deaths. But he expressed hope about the prospects for a successful vaccine, saying "we are fortunate because the first one out of the gate is more than 90 percent, probably close to 95 percent effective." He also said a second vaccine that's currently being developed may be successful as well.