DES MOINES, Iowa (AP) — Nestled between corn dog stands, animal barns and booths touting hot tubs and John Deere tractors, a Hy-Vee pharmacist and several nurses have been administering COVID-19 vaccines at the Iowa State Fair to anyone eligible that wants one.

Their booth didn’t have the long lines of more popular attractions, but by Monday more than 150 people had received a shot since the 11-day fair started on Thursday. More than 400,000 people attended the fair in its first four days.

Still, in a state where only half of the population is fully vaccinated, pharmacist Tiffany Aljets was encouraged that people were changing their minds.

“I think the (delta) variant has swayed a lot of people that weren’t sure if they wanted it or not, and a lot of people with kids want to get their kids back in school,” Aljets said Monday.

State fairs in Illinois, Indiana, Minnesota and Wisconsin also are offering COVID-19 vaccinations as the delta variant spreads nationwide and relaxed masking leaves public health officials concerned about another surge in infections.

At the Iowa State Fair on Monday, three people got vaccinated in the first two hours. Elsewhere on the fairgrounds, people stood close together in lines for rides, cheese on a stick and funnel cakes. Others pushed baby strollers through crowded barns housing sheep, pigs, cows and horses with electric fans pushing air around on a sunny 82-degree day.

Masks were rare, although some wore them inside buildings.

Fair officials canceled the 2020 event due to COVID-19 but are following Republican Gov. Kim Reynolds’ policy of personal responsibility by allowing fairgoers this year to decide whether to be vaccinated or wear a mask. Public health officials recommend wearing a mask where there are crowds.

The positivity rate in Polk County, where the fairgrounds are located, has increased to nearly 11%, according to Centers for Disease Control and Prevention data. Cases have accelerated rapidly in August, increasing by nearly 42% in the past week to a seven-day average of 758.

All but three of Iowa’s 99 counties are experiencing a substantial or high rate of spread, and the state’s vaccination rate has stalled at about 50% fully vaccinated.

Meanwhile, the fair is on track to attract an estimated 1 million visitors.

Doctors were concerned that a surge in delta variant infections could come at an already challenging time for hospitals.

“It’s not a matter of will we see increased cases, it’s just a matter of how many,” said Dr. Clint Hawthorne, an emergency medicine specialist in Des Moines. “If we were to experience a surge of COVID patients, we’re going to be in some big trouble because of our capacity issues that are at hand currently which are not COVID related.”

Des Moines has an acute shortage of nurses, so even if beds are available there aren’t nurses to tend to them and patients can’t be placed. Even now, patients coming into the emergency department can wait 10 hours for a regular hospital bed, he said.

Several Iowa fairgoers got vaccinated because of fears about the delta variant, or because family members have been sick and they understand how serious COVID-19 can be. Others have jobs that require vaccinations, Aljets said.

Jesse James, 13, of Pleasantville, rolled up his sleeve for a Pfizer shot on Monday. His mother, Angela Collins, said he’s going on a class trip to Washington, D.C., in October and she wants him vaccinated before he flies.

Both acknowledged a driving force behind the decision was his grandmother.

“I’m going back to school this year and my grandma kind of nudged me into getting a vaccine,” he said. “I mostly agreed with her.”

Jonila Shehu, 18, saw the Hy-Vee display was offering the Johnson & Johnson vaccine and decided to get her shot.

Shehu is an American Cultural Exchange Service foreign exchange student from Kosovo was attending the fair with her host mother Tammy Beeson, of Bettendorf. She had been in the U.S. for four days and is preparing to go to college.

“I know that I’m going to be with people and it’s important to me to keep myself and others safe,” she said.

In Wisconsin, 608 people were vaccinated during the state fair’s 11-day run, perhaps enticed by the promise of a free cream puff pastry. The push to vaccinate at the fair came as COVID-19 cases in Wisconsin hit their highest seven-day average since February.

At the Indiana State Fair, which opened July 30, Indiana University Health is offering Pfizer and Johnson & Johnson vaccinations daily. Spokeswoman Sophie Maccagnone said 304 vaccines were administered as of Monday. The fair will last more than three weeks, to spread out crowds and allow for fairground cleaning. The fair typically draws nearly 1 million people, and masks are not required.

Vaccines also will be offered by the Minnesota Department of Health, Ramsey County and Homeland Health at the Minnesota State Fair, which begins Aug. 26 and lasts for 12 days. Two million visitors typically attend.

At the 11-day Illinois State Fair, which began last Thursday, 156 shots were given through Monday, according to the Illinois Department of Public Health. Nearly 78% of them were given the single-dose Johnson & Johnson vaccine.