DENVER -- A lot of people won't get a flu shot if it's not convenient, which is why Bonnie Thomas, president and CEO of Colorado Wellness Connection, usually offers hundreds of on-site clinics.

"We go into businesses, churches, rec centers and community hospitals… to make it easy for people," said Thomas.

She just found out last week, though, that the vaccine she's been waiting for isn't coming.

"This is what we would call a spot shortage," she said.

Some flu vaccine distributors are running out of the vaccine because of record demand and because drug makers are turning their attention to the H1N1 vaccine, said Thomas.

She said more seasonal flu vaccine is supposed to be available in November, but in the meantime, she and other area flu clinic organizers have had to cancel more than 400 clinics across the Denver metro.

Some doctors' offices have also reported shortages.

But Target, Walgreens and local grocery stores such as King Soopers and Safeway have said they have plenty of flu shots.

"We are in a great position not to run out," said Brian Pavur, director of pharmacy Operations for Safeway. "We've partnered with three different vendors so we really spread out our purchasing to limit any liability."

It's not as convenient as the on-site clinic coming to you, but it's available on just about every corner.

There is a catch, though, many of the sites can't vaccinate children younger than 9 years old.

Children's Hospital is offering a flu shot clinic on Oct. 17.

You can find all the places to get flu shots in your area at immunizecolorado.com.