In this new reality, a single national strategy no longer makes sense. On Thursday, the White House announced that it would be sending “surge response” teams to hot spots with rising caseloads and low vaccination rates. The COVID-19 situation in different parts of the country has diverged so much now that Peter Hotez, a vaccine expert at Baylor College of Medicine, has suggested that the CDC issue two separate sets of guidelines.
Delta’s increased transmissibility only exacerbates the divide between the inoculated and the un-inoculated. As my colleague Ed Yong writes, “Vaccinated people are safer than ever despite the variants. But unvaccinated people are in more danger than ever because of the variants.” For people who are fully vaccinated, Delta poses very little direct threat. Its mutations do erode immunity slightly, but most breakthrough infections that result are mild or even asymptomatic. For entirely unvaccinated people, however, this means that Delta actually poses a double danger. They cannot rely on direct immunity from a vaccine, of course. But they also cannot rely as much on the herd immunity of vaccinated people around them if the variant is causing more breakthrough infections
The U.S. was always going to struggle to vaccinate its way to the herd-immunity threshold for COVID-19—the point at which enough people have gained immunity that viral spread is limited. As I wrote in February, America’s vaccine reluctance and the evolution of new variants that can evade vaccines make herd immunity difficult to achieve and maintain. The upshot is that the coronavirus will keep circulating, looking for new bodies it can infect. For the unvaccinated, getting infected is probably a matter of time. “Everybody will end up getting immunity to this virus eventually,” Jha told me. “You’ll either get it through vaccination or infection.”