People with chronic health conditions will have an opportunity to receive the swine flu vaccine at a public clinic set for Friday in Casper.

The clinic will run from 8 a.m. to 4 p.m. at Casper-Natrona County Health Department. It will only be open to people ages 25 to 64 with chronic health problems like diabetes and heart disease, according to department spokeswoman Jillian Riddle.

Vaccinations will be free.

Health officials have already held two swine flu clinics this month, each focusing on different groups that are at high risk of infection from the H1N1 virus. An additional round of clinics is also set for Dec. 3 at Cottonwood Elementary and Kelly Walsh High schools.

Although flu activity in Wyoming remains widespread, its growth has begun to slow, state health officials say. More than 660 cases of swine flu have been confirmed by the Wyoming Health Department since late May.

The actual number of cases is likely much higher since most people who become ill don't seek treatment or get tested.

Reach reporter Joshua Wolfson at (307) 266-0582 or at josh.wolfson@trib.com. Visit tribtown.trib.com/JoshuaWolfson/blog to read his blog.