Unvaccinated Americans are catching COVID-19 and telling doctors they're 'shocked' the virus is real

Doctors are voicing frustration as Americans continue to be hospitalized for coronavirus despite the widespread availability of a free, safe, and effective vaccines.

"It is heart-wrenching to see unvaccinated individuals come into the hospital with regret," Dr. Ryan Dare of the University of Arkansas for Medical Sciences in Little Rock told NBC News.

He told the network the hospitalizations are "nearly 100 percent preventable."

He noted treating clients who, "if they could do it all over again, would have had the vaccine in a second."

On Tuesday, Republican Gov. Asa Hutchinson admitted his state was "losing ground" in the battle against the pandemic.

Public health professionals are also struggling to deal with the Delta variant of the virus.

"It's just a mess," Dr. Mayrol Juarez told NBC News. "Everybody in the hospital is doing extra shifts, calling out for other hospitals to help."

Juarez reported he has patients who are "shocked" that coronavirus exists and can be fatal.

"A comment they make all the time is that they wish that they knew they were going to end up in the hospital this sick and they would have made a different choice and got the vaccine," he said.

Wyoming is also suffering, with only a 35% vaccination rate.

Dr. Andy Dunn, a family physician and chief of staff at Wyoming Medical Center in Casper, said he is "beyond frustrated."

"Whether it's the cowboy way or whatever, the mentality of so much of Wyoming is just 'we're not doing it.' It's really horrible and heartbreaking," he told NBC News.