The latest subvariant of the novel coronavirus to become dominant in Europe, the United States, and other places is also, in many ways, the worst so far. The BA.5 subvariant of the basic Omicron variant appears to be more contagious than any previous form of the virus. It’s apparently better at dodging our antibodies, too - meaning it might be more likely to cause breakthrough and repeat infections. Vaccines and boosters are still the best defense. There are even Omicron-specific booster jabs in development that, in coming months, could make the best vaccines more effective against BA.5 and its genetic...