Dan Clark needs a walker or a wheelchair to get around, but with rehab he's a lot better than a few years ago.

"I was unable to move any part of my body, but blink my eyes and click my tongue," Clark explains.

Clark has Guillain-Barre Syndrome. He was diagnosed after he received the flu vaccine in 2008.

"Woke up with a crick in my neck and then in about an hour or two later my arm was tingling a little bit," Clark explains.

Within 12 hours Clark was on a ventilator in the ICU. He stayed there for seven months. "My body basically just shut down," he says.

"GBS is what we call a polyneuropathy. Its a syndrome that attacks your auto immune system and your immune system attacks your nerve cells," says Dr. Lisa Broyles at the Doctors Express Urgent Care in Hixson.

Broyles says the chance of getting GBS is one in 100,000 and getting it from the flu vaccine is about one in a million.

"We only see about 20 to 30 percent of people that have had GBS that do have any residual deficit. So that means 70 to 80 percent will fully recover," Broyles says.

Clark is one of the 20 to 30 percent who will never fully recover.

"I would like people to be educated as far as if they really need to look and think if they really need to have that vaccination. They could be just like me, that one in a million or one in 100,000," says Clark.

Broyles says complications from the vaccine are typically rare. You have a better chance of getting GBS from the flu itself than from the vaccine.

"It does happen, and it is unfortunate when it does but it would happen more if more people didn't receive the vaccine," says Broyles. 

However, Clark remains a good example of the worst case scenario. "You can have things happen and people need to look into it and read the small print."