One in 5 residents in Dallas say they have no intention of getting the COVID-19 vaccine, with more than half of that group saying nothing can change their mind, according to a new study published in Scientific Reports.

The study compared COVID-19 vaccine acceptance nationwide to those in metropolitan areas. Researchers surveyed more than 6,000 people nationwide and sent the same survey to four major U.S. cities: Dallas, New York City, Los Angeles and Chicago.

Researchers found that about 19 percent of Dallas residents were opposed to COVID-19 vaccination, which is close to the national average of 21.4 percent. New York, Los Angeles and Chicago polled significantly lower, with only 10 to 12 percent opposed to vaccines. 

Half of the unvaccinated group in Dallas said nothing will change their minds. Reassurance from family members or recommendations from doctors were reported “unlikely” to change this opinion, according to the study. 

The main reason for the hesitancy was "waiting to see if there are no serious complications."

Jeffrey Lazarus, a professor at the Barcelona Institute of Global Health at University of Barcelona in Spain and co-author of the study, said that the refusal by such a large segment of the population is going to be “one of the problems we’re going to have in ending this pandemic,” according to The Dallas Morning News, which reported on the study. 

He said he was worried about increasing cases with the Thanksgiving holiday. “I think we’re going to see a spike in cases, and it will be particularly among the unvaccinated,” he told the Morning News. 

While the data was consistent with other public polling, it found that race was not a consistent indicator of vaccine hesitancy, which other studies have reported in the past.

“These findings caution against demographic generalizations regarding vaccine acceptance,” the study reads. “Stereotyping racial attitudes could even lead to disenfranchisement of communities of color that are increasingly well-motivated to participate in vaccination programs."