Frank Scott unbuttoned his shirt, rolled up the exposed white T-shirt sleeve beneath, and prepared to get the jab. On March 12, Scott, the mayor of Little Rock, Arkansas, was sitting in a wooden chair in the Express Rx pharmacy surrounded by cameras in an effort to help ease his constituents’ fears about the COVID-19 vaccine. Scott has never been a fan of getting shots—and had never had a flu shot before—but this one was different. He’s lost loved ones to the coronavirus; hundreds have died in his city. Almost as soon as his shot began, it was over. It was a year to the day since Scott had declared a state of emergency—implementing a curfew, prohibiting large gatherings, and closing community centers. As he sat there, with vaccines starting to become widely available, the crisis looked like it might soon be ending.

Four months later, however, only a third of Arkansans are fully vaccinated. The hospitals in Little Rock, which Scott often calls the state’s health-care mecca, are near capacity, with a new surge under way. And city and state leaders are struggling to get residents who are hesitant, apathetic, or antagonistic toward vaccination to get the shot. “We’ve been on the ground like it’s a campaign trying to get it done,” Scott told me. “But we spend a lot of time dispelling mistruths, misinformation, and conspiracy theories.”

Little Rock is not alone in its region. A recent study by researchers at Georgetown University, led by Shweta Bansal, an associate professor and an infectious-disease expert, identified locations where vaccination rates are lower than the national average, and crucially, that are also surrounded by other areas with low vaccination rates. They homed in on five specific regions, which they say are the most vulnerable to future outbreaks; four are in the Southeast, and one lies just adjacent. One area they pinpointed is a cluster of counties that covers the majority of southeast Alabama, stretching into Georgia and Florida; another spans the northwest part of Alabama into northwest Mississippi and Tennessee; a third covers the boot heel of Missouri and into north Arkansas; and a fourth cluster in north and west Louisiana stretches into east Texas. The final, most expansive cluster, just to the west of the southeastern region, blankets the Texas panhandle and extends into Oklahoma and New Mexico.

The outbreak that America is now seeing is exactly what Bansal and her team would expect based on their research. As Bansal puts it, “Unvaccinated individuals are efficient fuel like dry wood for the fire of future outbreaks. Vaccinated individuals are like soaked wood—while it can’t easily catch fire, if it’s surrounded by dry wood, the chances are much higher.” In other words, low vaccination rates in the South make this moment less safe for everyone there, and over time could jeopardize the country’s hope of ever getting the novel coronavirus more under control.

One reason public-health officials and local, state, and federal leaders have struggled to persuade the unvaccinated to take the leap is because the explanations people have for why they remain unvaccinated are so varied. “Low vaccine uptake is being driven by a confluence of factors that are being subsumed under the term hesitancy,” Henna Budhwani, a public-health professor at the University of Alabama at Birmingham who studies vaccine hesitancy, told me. Some people might be skeptical of the vaccines, and some people don’t want to discuss them with anyone—not even their doctor, she said. Meanwhile, she added, some people in rural locations may not have access to vaccination sites at times that work with their job, while “others feel that public health is telling them what to do, and because they feel that this messaging is promoting an infringement on their autonomy, they are responding with defiance.”

And because of the various causes, attributing the low rates to one group is difficult. In a state like Alabama, for instance, roughly 30 percent of white people, 27 percent of Black people, and 22 percent of Hispanic residents are vaccinated. “Regardless of race, the rates are abysmal,” Budhwani said. As such, “we need to respectfully reach into communities,” she continued, and that means continuing to engage with churches and schools as well as leaning on peer-to-peer messaging. “People tend to respond better when hearing public-health messaging from near peers, so for example, when trying to engage adolescents in Alabama, we should co-create messaging with adolescents and then these same adolescents should be involved in the delivery of the messages that they helped to create.”

In several large southern metropolitan areas, access to the vaccines is not as much of an issue as it once was. “You can go any place: Walmart, Kroger, the community center, and get the vaccine,” Scott told me, commending Arkansas’s Republican governor, Asa Hutchinson, and public-health officials for making the vaccines freely and widely available. Still, some politicians have continued to disparage the vaccines. Earlier this week, Representative Mo Brooks of Alabama sent a letter to President Joe Biden imploring him to overrule a mask mandate for unvaccinated people at Fort Rucker, the military installation. “Our soldiers should not be intimidated or coerced by the government into taking an experimental shot that has death and other ill-effect risk associated with it,” Brooks wrote, in the exact sort of mistruth Budhwani and other public-health researchers hope to dispel.

When I asked Scott what the best-case scenario for Little Rock is at the moment, he told me that he hopes to have 50 percent of his residents fully vaccinated by the end of August. Such a schedule would put them in good shape for the fall—though he can’t allow himself to worry that far out right now. “We have hospitals that are concerned on whether or not to take a COVID patient versus non-COVID,” he said. “I just want to get through the summer, in a successful way, with lives—literally, we have folks losing their lives for something that’s preventable.”

Bansal remains optimistic about the chances for increasing vaccination rates—but that is, in part, because she feels that she has to. “I’m not sure I would have gotten through any of the last 16 or 17 months without optimism,” she told me. Still, she worries that without improved vaccination in the South, America will be stuck in a perpetual cycle of coronavirus waves.

As Budhwani put it, “Vaccines work. Vaccines save lives.” People just need to roll up their sleeves to get them.