The unvaccinated fall into two groups, the vaccine hesitant and the vaccine resistant:
As coronavirus cases rise across the United States, the fight against the pandemic is focused on an estimated 93 million people who are eligible for shots but have chosen not to get them. These are the Americans who are most vulnerable to serious illness from the highly contagious Delta variant and most likely to carry the virus, spreading it further.
It turns out, though, that this is not a single set of Americans, but in many ways two.
In one group are those who say they are adamant in their refusal of the coronavirus vaccines; they include a mix of people but tend to be disproportionately white, rural, evangelical Christian and politically conservative, surveys show.
In the other are those who say they are open to getting a shot but have been putting it off or want to wait and see before making a decision; they are a broad range of people, but tend to be a more diverse and urban group, including many younger people, Black and Latino Americans, and Democrats.
With cases surging and hospitalizations rising, health officials are making progress in inoculating this second group, who surveys suggest account for less than half of all unvaccinated adults in the United States.
The problem is the same surveys show that the group firmly opposed to the vaccines outnumbers those willing to be swayed. And unless the nation finds a way to persuade the unwavering, escaping the virus's grip will be a long way off, because they make up as much as 20 percent of the adult population.