As the number of COVID-19 hospitalizations dramatically decline across America, health care experts note that patients who are admitted have one thing in common: they are not vaccinated. Nearly every patient admitted to a hospital nationwide has not received the COVID-19 vaccines, according to USA Today.

“Less than 1% of our hospitalized COVID-19 patients are vaccinated,” said Dr. Mark R. Sannes, an infectious disease expert in Saint Louis Park, Minnesota, who is affiliated with multiple hospitals in the area. That trend has been mirrored in other hospital systems across the country showing that overwhelmingly, people who are unvaccinated are the ones getting sick with COVID-19.

Data from the Centers for Disease Control and Prevention along with statistics gathered by the Department of Health and Human Services, reveal that those states with the lowest vaccination rates are also the ones with the highest number of COVID-19 patients in intensive care units.

According to USA Today, Wyoming, Missouri, Arkansas, and Idaho have vaccinated fewer than 40% of their population and have the highest percentage of COVID-19 patients in their ICUs. And those affected by severe illness tend to be much younger than the hospitalized patients early in the pandemic since people over the age of 65 are more likely to be fully vaccinated.

“We’re all seeing the same thing—when someone does get sick and comes to the hospital, they’re much more likely to be young and unvaccinated,” said Dr. Robert Wachter, chair of the Department of Medicine at the University of California San Francisco.

About one if five U.S. adults are still reluctant to get a COVID-19 vaccine according to a poll released in April by the Monmouth University Polling Institute. According to The Hill, 21% of adults polled said they would not get inoculated, down marginally from the 24% who said the same in a March poll. Twelve percent said they would let others go first “to see how it goes.”

“The number of people who have been skittish about the vaccine has dropped as more Americans line up for the shot, but the hard-core group who want to avoid it at all costs has barely budged,” said Patrick Murray, director of the Institute.

Medical experts say vaccine hesitancy is due to multiple factors. People still have questions about the safety of COVID-19 vaccines, according to USA Today, and some fear there will be repercussions from the shots, either financially or health wise.

Dr. Gerald Maloney, chief medical officer of Geisinger Hospitals in Pennsylvania, said that the people who say “It’s my body, my choice” when it comes to declining vaccines are self-serving.

“It’s not all about you,” he said. “It’s also about the people around you.” Pediatricians at hospitals across America say that the children who have been admitted for COVID-19 or its serious aftereffect, multisystem inflammatory syndrome, or MIS-C, have not been vaccinated or live in households where individuals did not get their shots.

Health care experts say the message is clear: They are not seeing many vaccinated people get sick, says USA Today.

“Vaccination works in preventing severe COVID-19 illness,” said Cathy Bennett, president of the New Jersey Hospital Association.