After flitting through urban centers, Omicron will find these isolated enclaves. It will pummel them. It will cause debilitating disease and death, but generate perhaps only a flimsy veneer of protection that, unbuttressed by vaccines, might not successfully ward off future waves. By one estimate, a third to half of all Americans may end up infected by Omicron by mid-February. The variant will not encounter all of those people on equal immunological footing, nor will it create such footing. “Some people will be left with immune houses of straw, others of wood, others of brick,” Sosin said. The virus is not an equalizer; it never has been.

Appending vaccinations on top of recent Omicron infections in less protected places could help even the playing field—but there may not be incentive to, as Omicron cases eventually fall away. In many parts of the country where vaccinations have struggled to gain traction, “there is a predominant belief that infection means you are now immune, especially if you were quite sick,” Hidalgo told me. If uptake of shots continues to be sluggish, the gaps in protection that existed before Omicron only stand to widen. This is the texture that national curves and figures obscure: knots of vulnerability that many Americans can easily ignore, but that the virus all too easily exploits.