DES MOINES – Mandi McClue rolled up her sleeve, extended her arm and looked away as a nurse stuck her with a syringe that contained the mumps vaccine.

The 22-year-old pharmacy student was attending a free immunization clinic at the Drake University Student Health Center on Wednesday.

“It’s better to be safe than sorry,” McClue said as she left the clinic, where a handful of students waited for the shots.

The state last week announced mass immunization clinics for 18- to 22-year-olds as the number of mumps cases in Iowa increased daily. The latest figures showed 1,120 probable, confirmed and suspected cases in Iowa.

Public health officials divvied up 25,000 doses of the vaccine among 35 counties where colleges and universities are centered.

Students, as well as other young adults they socialize with, were encouraged to check whether they’ve received the two recommended doses of the measles-mumps-rubella vaccine.

Mary Mincer Hansen, Iowa’s public health director, has said the state is focusing on college-age Iowans because they are most likely to get the virus and spread it to other groups. People in that age group may have had only one MMR – the dose that was recommended when they were growing up, she said.

“We need to rely heavily on them if we are going to get mumps in Iowa stopped,” Hansen said in statement.

The free clinics were scheduled to run through Friday, with more planned for next month.

Even with the immunizations, about 10 percent of the population remains susceptible to the illness, and health officials have cautioned that more cases may be reported.