COVID-19 testing at home is both possible and reliable. Here’s what you need to know.

Remember when a COVID-19 diagnostic test meant waiting in your car for a nurse wearing head-to-toe PPE to shove a long swab down your throat and send the sample to a lab that would take a week or more to return results? That was so 2020. Now you can get molecular test kits delivered to your door — no prescription needed ― then mail a shallow nose swab or a saliva sample to a lab that returns results in a day or two. Or, if you’re willing to sacrifice some accuracy for convenience, you can order antigen tests online that give rapid results right at home. You may have to pay for the test, depend...