(CNN) More than 40% of the US population is now fully vaccinated against Covid-19, but many in the remaining 60% still face critical barriers to health care access that make it harder for even those who want the vaccine to get it.
Counties that are lagging behind the overall Covid-19 vaccination rate in the US tend to be poorer and less educated, with less access to computers and the internet, a CNN analysis of federal data has found.
This digital and economic divide contributes to disparities in health care access generally, experts say, and access to Covid-19 vaccines is no exception.
"With too many things in health, we focus on the individual behavior without looking at the systems that either make it easy or not for someone to practice that healthy behavior," Dr. Richard Besser, president and chief executive officer of the Robert Wood Johnson Foundation, told CNN.
In counties that lag behind the US average for vaccination coverage, an average of 35% more households do not have access to the internet and 39% more households do not have a computer.
"Health behaviors (like getting a Covid-19 vaccine) are, in part, a personal choice," Besser said. "But one of the things that's often said is that the choices we make depend on the choices that we have. For someone who doesn't have internet access, there's not much choice there in being able to go online and schedule your appointment."
And economic disparities are a root cause of these and many others, experts say.
In counties that have fully vaccinated a smaller share of their population than average, the median household income is about 20% less than in counties that have vaccinated a larger share, according to CNN's analysis.
In fact, a county's vaccination coverage jumps an average of 3 percentage points for every $10,000 more in median household income.
The average poverty rate is also higher in counties that have vaccinated a smaller share of their population -- about 16%, compared to about 12% in counties with higher vaccination rates -- and a smaller share of adults age 25 and older have received a Bachelor's degree or higher -- about 19%, compared to about 30%.
CNN's analysis used CDC's county-level vaccination data as of May 26, 2021, as well as data from the Census Bureau's 2019 American Community Survey 5-year estimates. The analysis excluded data from seven states where county information was not included in more than 15% of vaccination records.
A recent CDC study found that rural counties have vaccinated a smaller share of residents than urban counties in the US on average. And experts say the vaccination rates have been slower in rural counties for many of the same reasons Covid-19 incidence and death rates were higher in rural counties.
"The rural population is older, sicker and poorer in most places. That's who they are," Alan Morgan, chief executive officer of the National Rural Health Association told CNN. But it's also a much more diverse group than the conservative white men that tend to be focused on, he said.
The older population is generally well-covered in the US -- nearly three-quarters of people 65 and older are fully vaccinated, according to CDC data -- leaving the "sicker" and "poorer" parts of rural communities at risk.
"Poverty in a rural context is a huge driver for public health problems and concerns, longstanding," Morgan said.
Issues in both health care access and messaging are now at play, he says, and poverty intersects with both, creating barriers not just with transportation and internet access, but health literacy, too.
Many in rural communities still don't understand that it's free to get a Covid-19 vaccine and can't afford - or don't know how -- to take time away from work to get one, Morgan said.
While the daily pace of vaccinations has dropped in recent weeks, so has the share of Americans who say they are vaccine hesitant.
The next phase of the Covid-19 vaccination campaign will be slower and more deliberate, Besser said, but just as important.
"Now what we're seeing is a more steady, ongoing effort. It's harder work reaching people who have more barriers to being vaccinated," he said. "But I'm encouraged and optimistic that the interest will continue to be there."