HEFLIN, Ala. — Peyton Thetford straddles two Americas.

Inside the intensive care unit at the University of Alabama at Birmingham Hospital, the 27-year-old nurse has witnessed a dramatic uptick in COVID-19 patients struggling to breathe. But after grueling 12-hour shifts — moving patients from their backs to their stomachs and then turning them onto their sides every two hours to keep their oxygen levels up — he leaves the hospital and sees hardly anyone wearing masks or practicing social distancing.

“It’s kind of like the movie ‘Groundhog Day,’ where you wake up and everything’s the exact same, and you can’t do anything to change it,” he said. “You’re just coming to work and watching people die.”

As the U.S. reached the milestone last week of getting at least one dose of a vaccine into the arms of 70% of adults, few people were celebrating. The highly contagious Delta variant of the coronavirus was surging across the U.S., and there was growing exasperation that the project to stem the spread of the virus had stalled as it met resistance to vaccinations in large sections of the conservative South and Midwest.

The split between those who have received their COVID-19 shots and those who refuse follows familiar geographical and political fault lines.

Democratic-leaning states in the Northeast, such as Vermont and Massachusetts, lead the way in vaccinations, while staunchly Republican states that voted for former President Trump in 2020, including Alabama and Mississippi, have the lowest vaccination rates and the steepest increase in cases and hospitalizations.

Ever since the health crisis began, the coronavirus, in all its forms and variants, has magnified the nation’s political differences. Americans have disagreed on masks, government lockdowns and even the seriousness of a virus that has killed more than 617,000 people in the country.

“This is the most politicized I’ve ever seen America — and the tragedy is that it’s politicized over a life-and-death issue,” said Frank Luntz, a Republican pollster advising the Biden administration’s COVID-19 task force about how to reach people who are reluctant to get vaccinated.

As Delta has caused COVID-19 cases and hos- pitalizations across the U.S. to skyrocket, the highest number of infections and most severe outcomes are occurring in areas with low vaccination rates, according to the Centers for Disease Control and Prevention. But the pace of vaccinations has risen over the last few weeks, particularly in Southern states that have shown strong hesitancy.

Still, Alabama lags behind all other states, with just 40% of residents over the age of 12 fully vaccinated — compared with Vermont, which has fully inoculated nearly 77%. The number of COVID-19 patients in Alabama hospitals climbed in the last month to 2,134 from about 247. If the current rate of increase continues, the state’s hospitals could within a month exceed the January peak of 3,089 patients, the president of the Alabama Hospital Assn. has warned.

But many Alabama residents seem more worried about the vaccine than about the virus.

“I don’t want to be a guinea pig,” said Renee Dunn, 43. Dunn is a manager at Jack’s, a fast-food restaurant in Heflin, an east Alabama town that is the seat of Cleburne County, a rural area with one of the state’s lowest vaccination rates. According to the Alabama Department of Public Health, 1 in 4 Cleburne County residents over the age of 12 has been fully vaccinated.

Dunn worries that the vaccines were manufactured too quickly. Her mother had a bad reaction to a vaccine this year and suffered from sore joints, fever and confusion, she said, and her son felt so sick he missed a few days of work after taking his first shot.

Serious side effects are rare.

Dunn suffers from Crohn’s disease and arthritis — conditions that make her especially vulnerable to the effects of the virus — and contracted COVID-19 in December. She didn’t know last week if she still had antibodies that would protect her from future variants and had not sought her doctor’s advice about vaccines.

Politics, she said, have nothing to do with her reluctance. She did not vote in 2020. But she said one factor might change her mind: Food and Drug Administration approval of a vaccine.

Other residents of this staunchly conservative Alabama county, where nearly 9 in 10 voters cast ballots for Trump in 2020, are more resistant.

Ryan Jackson, a pharmacist who manages Wright Drug Co. in Heflin, said he has heard every reason to not get a shot: fear that the vaccines could lead to side effects such as infertility, belief that the risks of COVID-19 have been exaggerated, outlandish theories about the vaccines containing microchips for government tracking. Some of the biggest pushback has come from those who don’t trust the government.

“You hear the conspiracy theories; they don’t trust the government, a lot of political factors,” said Jackson, who is vaccinated. “It’s just a complete distrust of everybody in authority.”

As someone who knows most people in his small town — and has a pretty good idea of who has been vaccinated and who hasn’t — Jackson tends to not push back on conspiracy theories, he said. Instead, he focuses on people with legitimate questions, providing information about side effects and emphasizing that a vaccine decreases their chance of being hospitalized or dying of COVID-19.

A Republican, he dismissed the idea that the vaccine divide comes down to partisan politics.

“I’m about as conservative as you can get, and I’m about as pro-vax as you can be,” he said, noting that all of his family, most of his friends and 80% to 90% of the congregants of his church are vaccinated.

But surveys from the Kaiser Family Foundation indicate that the partisan gap on vaccinations is widening. In April, the average vaccination rate in counties that voted for Trump was 20.6%, compared with 22.8% in Biden counties. By July 6, that gap had increased to 11.7 percentage points.

Not all Republicans are on the same page. Some GOP lawmakers and officials have derided public health officials such as Dr. Anthony Fauci, the nation’s top infectious-diseases expert, and promoted misinformation, falsely accusing the Biden administration of trying to inoculate Americans against their will, even as many establishment Republican figures have promoted vaccines.

Sen. Mitch McConnell (R-Ky.) has urged Americans to get vaccinated, last month saying, “It’s not complicated.”

Even in Alabama, where most people remain unvaccinated, Republican Gov. Kay Ivey has said it is time for the vaccinated to push back. “It’s time to start blaming the unvaccinated folks, not the regular folks,” she told reporters last month. “It’s the unvaccinated folks that are letting us down.”

The Americans most likely to reject vaccines, Luntz said, voted for Trump, live in small towns and rural areas and are under the age of 70. Part of the problem, Luntz said, was that Trump was relatively silent on the issue as websites controlled by those opposed to the vaccines spread incorrect and misleading information.

Over the last few months, Luntz’s focus groups have become more resistant to vaccination, he said. At first, participants would ask questions; they rarely do anymore. Instead, he said, they counter with arguments they had read online and actively try to reject the facts presented.

“It has gone from hesitation to skepticism to cynicism — and now it’s rejection,” Luntz said. “There are millions of people who’ve made up their mind not to get the vaccine.”

As more patients are admitted each day to emergency rooms, many vaccinated Americans have lost patience with those who are hesitant or flat-out refuse. The indignation is most vocal in liberal urban hubs, where people abided by restrictions and hoped that mass vaccinations would bring life back to normal — allowing them to take off masks, dine indoors, return to schools and put the threat of COVID-19 behind them.

In Portland, Ore., where more than 4 in 5 residents ages 12 and older are vaccinated, Dean Gadda, a retired small-business owner who got vaccinated as soon as he could, lost his temper with a family that lives on his street, he said.

One of the family’s three grown children, a man in his mid-20s, had gone to Gadda’s home in a solidly Democratic neighborhood to play fiddle. Later, Gadda, a 73-year-old Democrat, asked the man whether he’d been vaccinated.

No, his neighbor said. No one in the family had been vaccinated — and all five were sick with COVID-19. He said he wasn’t concerned because no one was very ill.

“Well, you’re no longer welcome here. Don’t even come up my driveway,” Gadda said he told the man. “I don’t care about you. I care about all the people you’re going to infect.”

Even families that are politically aligned struggle to see eye to eye.

In Sugar Land, Texas, Tricia Doyle, 61, a real-estate administrator, received a vaccine but worried that her two sons in Denver had not gotten inoculated “because of all the misinformation.”

Doyle and her sons are Republicans who voted for Trump, she said, but neither of her sons believe in conspiracy theories. They’re not opposed to vaccinations in general. Doyle caught COVID-19 in January, and her whole family knows it’s real. But they distrust the federal government.

“We definitely need to come together as a nation and get the facts out there,” she said. “People are just questioning everything.”

Some public health experts say America is not entrenched in two camps — vaxxers and anti-vaxxers — and there is a difference between hesitance and opposition.

“Those who are skeptical about the COVID-19 vaccine are not a monolith,” said Henna Budhwani, assistant professor of public health at the University of Alabama at Birmingham, who has studied vaccine hesitancy among Black Americans in the South.

In Alabama, she noted, the percentage of white and Black residents getting their first shots is about the same — 32.5% of white residents and 33% of Black residents.

Although Alabama is one of the nation’s most conservative states, it is a predominantly rural state with a higher percentage of Black residents than the nation as a whole and a dismal record of health inequities.

Trust is a particular issue among Black Alabamans, many of whom remember the U.S. government’s 40-year-long syphilis experiment in Tuskegee, which involved withholding treatment from hundreds of Black men.

Budhwani said Americans have all kinds of reasons for declining vaccinations, whether it’s fear of needles, distrust of the government’s intentions, suspicion about the speed of vaccine development or confusion over what they perceive to be unclear or mixed government messaging.

Others, she said, believe that the effects of COVID-19 have been exaggerated or that the virus will not affect them. Some are forcefully rebelling against what they view as infringement on their autonomy.

Persuading people, she said, would involve public health messaging developed and delivered by trusted members of the community, such as church leaders and teachers.

There is reason for hope. Despite political polarization, some conservative states with the highest rates of daily new cases, including Alabama, are seeing the biggest jumps in vaccination rates.

At Wright Drug Co. in Heflin, Jackson has started to see a slight uptick in demand, he said, from fewer than 10 vaccinations a week in June to more than 20 a week — nothing like the initial demand for 200 to 250 shots a week, but enough to raise his confidence.

“It’s not too late,” he said. “I think the longer we go, people will see that we’re not growing extra limbs and third eyeballs. More people will come around.”

Jarvie reported from Cleburne County, Ala.; Read from Seattle; and Hennessy-Fiske from Fort Bend County, Texas.