A new COVID-19 variant called XBB.1.5 is driving a new wave of infections.

But susceptibility to it is not, as some contend, being fueled by vaccines. Still, the surges of ever more immune-evasive variants raise legitimate questions about whether vaccines and boosters are still protecting us from infection, or should only be recommended for their ability to prevent severe disease and death.

Jeremy Luban, a virologist at the University of Massachusetts, says XBB.1.5 has made a massive leap above existing variants. He compares the other currently circulating variants to athletes slowly shaving off a hundredth of a second on the 100-meter dash. But XBB.1.5 is like Usain Bolt, suddenly smashing the old record by a huge margin.