NASHVILLE, Tenn. - Vanderbilt University Medical Center is one of eight locations across the country testing the vaccine for the H1N1 virus and is about to launch its second round of trials.

Beginning Wednesday, children will be rolling up their sleeves at the Nashville hospital but participants are still needed.

Dr. John Williams, who specializes in pediatric infectious diseases, is taking part in the adult trials and has signed up his four children up.

He told News 2 if he thought it wasn't safe, he wouldn't let them do it.

"As a parent, my kids have taken part in vaccine trials before and they're old enough and they understand the value of what they're doing," he said.  "...They're doing something to help other children."

While Vanderbilt had more than enough adults for round one of the vaccine trials, researchers need 30 more children from six months to 35 months old, and 20 more children between the ages of three and nine.

According to Dr. Williams, parents seem to have two schools of thought on allowing their children to participate.

"I've heard from friends of ours, parents who are afraid because of all the chatter about H1N1, and then people who have concerns about H1N1 and want to get the vaccine, and if they can get it as part of a trial, then they are willing to participate," he said.

As for side effects, Dr. Williams said he's spoken to two adults who've had the shot and they said besides having a soar arm for a couple of days, which happens with any shot, they feel fine.

The trial lasts eight months.

Participating in the children's vaccine trials pays $350.

Click here for more information or call 615-322-2730 or email vaccineresearch@vanderbilt.edu if you are interested in participating.