 Meantime, President Biden tests positive for COVID while traveling in Las Vegas. He has mild symptoms. CBS News Dr. John LaPook on what to expect. There's a risk in an older person who's got some atrial fibrillation. He's on medication. This is not risk-free. But we know statistically if he was vaccinated and he was boosted and now he's getting medication, he's followed closely. You keep looking at him closely because...