About a week before Christmas, during one of its periodic teleconference briefings that have the approximate aesthetic of a cheap 1960s science fiction movie imagining an Orwellian future, the White House COVID-19 Response Team again gathered to talk to the people. The government appeared ready to disown half the country. On Dec. 17, with video feeds of Dr. Anthony Fauci and Dr. Rochelle Walensky hovering over either shoulder, response team coordinator Jeffrey Zients sat calmly before a pandemic-weary public whom he addressed not as a whole but as two halves fundamentally at odds with one another: the vaccinated and the unvaccinated. “We are intent on not letting omicron disrupt work and school for the vaccinated,” Zients said. “You’ve done the right thing, and we will get through this.” But for those who have chosen not...