After two-plus years of erupting into peaks, the American coronavirus-case curve has shifted to a never-ending plateau. Waves are now so frequent that they’re colliding and uplifting like tectonic plates, the valleys between them filling with virological rubble. Nothing yet suggests that SARS-CoV-2 has juiced up its ability to mutate. But subvariants are slamming us faster because, from the virus’s perspective, “there’s more immune pressure now,” says Katia Koelle, PhD an evolutionary virologist at Emory University.