Last week, on my kids’ fourth day of in-person school, I came down with my first sore throat in six months. At first, I downplayed it — it was just allergies. Then I panicked and had to take a Xanax. Then I thought: How the heck could I have gotten sick? My kids and husband seemed perfectly healthy, and other than their school, which was being held entirely outside, the riskiest place I’d been over the past two weeks was the Walmart parking lot — once — to pick up curbside groceries.