But partisanship isn’t the only thing that has shaped Americans’ vaccination status. Unvaccinated Americans tend to be younger, less well-educated and poorer; they are also more likely to be a person of color. The situation we’re in is not just because of politics but also because of access to the vaccine and broader skepticism of the health care system.

Age is an even more significant dividing line for vaccinations than politics is. Older Americans are far more likely to be vaccinated, undoubtedly because they were prioritized in the vaccination rollout since they’re more at risk from coronavirus infections. About 80 percent of Americans age 65 or older are fully vaccinated, according to the Centers for Disease Control and Prevention, compared with about 55 percent of Americans 18 to 64. Within that 18-64 range, the younger the age group, the less likely it is to be vaccinated relative to its share of the population.

Some degree of skepticism or uncertainty may be playing a role in why young people are not as likely to be vaccinated. The CDC reported in June that from March to May, nearly half of American adults under 40 either were unsure about the vaccine or didn’t plan on getting one. Polls suggest that there may be less skepticism now, as the Public Religion Research Institute recently found that the share of Americans under age 50 who were hesitant or opposed to getting the vaccine fell from slightly more than 50 percent in March to 35 percent in June. Still, just under half of that group of 35 percent remained opposed to getting vaccinated in the June survey.