At-home Covid-19 test kits: How do they work, and where to buy online Updated Apr 27, 2021; Facebook Share Covid-19 vaccination efforts are in full swing in the United States with more than 89 million people fully vaccinated across the country, according to the Centers for Disease Control and Prevention. But that doesn’t mean it’s time to start letting our guards down. Testing is as important as ever, and easily accessible testing with rapid results may become even more important as more businesses, venues and schools reopen, and the summer season of concerts, youth sports and travel kick into high gear.