Dustin Lee could barely contain his anger as he recalled how an unvaccinated health care worker nearly set off a COVID-19 outbreak at a senior home operated by his company in central Minnesota.

Lee, president and CEO of Prairie Senior Cottages, said the worker, employed by an outside hospice agency, provided care to four residents over an eight-hour shift without ever informing them that she had declined to be vaccinated against the deadly coronavirus. Days later, Lee learned that the unvaccinated worker was infected, forcing the facility to shut its doors to family visitors and begin testing all its residents and staff.

"My blood is boiling," said Lee, his voice trembling. "We have worked so hard for so long to protect our residents … and right now we have mothers who may not be able to see their loved ones on Mother's Day. Folks need to get the shots."

Four months after vaccines became available, senior care communities across Minnesota continue to face a daunting challenge: how to persuade front-line workers to overcome their fears and embrace the lifesaving shots.

A large percentage of nursing home and assisted-living workers continue to refuse the vaccines, posing a major challenge to the state's efforts to prevent further virus surges in facilities that care for the state's most vulnerable residents.

Their wariness is fueled by a wide array of concerns, including fears of long-term side effects, particularly among women of childbearing age; doubts about the vaccine's efficacy; distrust in the medical system, and perceived immunity among workers who have recovered from COVID-19, according to facility administrators and industry representatives.

Across the state, senior homes have tried everything short of mandating the shots to persuade workers to roll up their sleeves. They have bombarded them with text messages and social media postings. They have held vaccine parties and given out gift cards. They have asked respected workers to sway their reluctant colleagues through one-on-one conversations. And they've handed out scientific reports showing how the vaccines have been highly effective in reducing hospitalizations and deaths, particularly among older adults.

These efforts are driven by a sense of urgency. After seeing the number of COVID-19 infections and deaths plunge this year, long-term care providers want to avoid a return to the harrowing outbreaks of last spring and fall, when the disease was claiming dozens of lives a week in these facilities while plunging the industry into a full-blown staffing crisis.

"We're at that point where we have to find a new magic bullet to get the rest of the folks on board," said Amanda Johnson, a nurse and vice president of clinical operations at Tealwood Senior Living, a Bloomington-based company that operates 30 senior facilities in Minnesota. "Everyone wants to get back to normal but we will never get there until a majority of our staff get the shots."

Yet thousands of front-line workers remain unconvinced. New survey data released by the Minnesota Department of Health show that only about half of workers in assisted-living facilities have received both shots, while nearly 60% of those in skilled nursing homes are fully vaccinated. By contrast, more than 80% of those who live in these facilities have agreed to be vaccinated, according to a voluntary survey of long-term care providers.

A federal study released late last month underscores the urgency. At a Kentucky nursing home, an unvaccinated staff member brought in a variant, or new strain of the virus, causing 18 residents and four workers who had been fully vaccinated to contract the virus, according to the study by the Centers for Disease Control and Prevention. Unvaccinated residents and health care staff had three and four times the risk of infection during the outbreak as vaccinated residents and staffers, respectively, the study found.

Debra Howze, a professional caregiver from St. Paul who works in a seniors' apartment complex, rattled off a half-dozen reasons why she refuses to get vaccinated. Her biggest concern is that she thinks the vaccines were rushed through development for political reasons, and she is not convinced it will protect her against the constantly mutating virus and the emerging variants. Howze already survived a bout of COVID-19 last year and believes the experience has given her some immunity against the disease.

"People keep saying, 'You gotta get the shots,' because they are just accepting everything the government says," Howze said. "But I'm afraid of what [the vaccine] will do to my body. What if I get the shot and something happens that is worse than COVID itself?"

Ageane Reed, an office manager at Oak Meadows Senior Living in Oakdale, is also reluctant. She recounted how both of her sons became sickened after getting vaccinated as infants. She also has doubts about how scientists were able to conduct adequate testing for vaccines that normally take years to develop. At the same time, Reed said she has close relatives and friends who have gotten the shots without suffering serious side effects. And she is concerned that, by not getting vaccinated, she will be unable to see them.

"What it comes down to is, I want my freedom back," Reed said. "But I also don't want to put stuff in my body that isn't necessary."

Some providers said they weighed the possibility of requiring the vaccines but ruled it out because they feared losing staff in the midst of a labor shortage. There is also no unifying reason that explains why workers are resistant to the shots — and hence no straightforward message or tactic to persuade them. Religious beliefs, misinformation on social media and speculation about long-term health effects have all played a role, say long-term care providers.

Increasingly, providers are turning to one-on-one conversations between workers as the most effective way to change minds. In recent weeks, dozens of long-term care facilities have begun to train trusted staff, known as "vaccine ambassadors," to listen to the misgivings of vaccine-hesitant co-workers while providing them with information about the safety of vaccines. These ambassadors then share their own experiences about getting the shots in an effort to gently persuade — but not pressure — workers to get vaccinated.

"Active listening is gigantic," said Alyson VanAhn, a psychologist who works in long-term care facilities and helped design the program. "We need to create an atmosphere in these facilities where [workers] who haven't been vaccinated feel comfortable walking up to a co-worker and talking to them about their concerns."