The newest coronavirus variant is raising alarms. The pandemic is not over.

Remember the promise of normalcy by July Fourth? How can it be that now — after Thanksgiving, after so much sacrifice and waiting, after the arrival of vaccines, after months of sweaty masks, distancing and isolation — that another wave of pandemic infection is upon us? In Europe, lockdowns are returning. In some hot spots such as Minnesota and Michigan, hospital wards are again overflowing. A worrying new variant is raising alarms. What happened?

It’s not all bad. The vaccination campaign has put at least one dose in the arms of more than...