A clinical trial for a new gene therapy treatment in the U.S. has restored a Leamington, Ont., boy's immune system.

Felix Quiring was just two weeks old in December 2014 when his parents first learned about severe combined immunodeficiency, a genetic disorder that made contracting simple viruses like the common cold an attack on his life.

The disorder became widely known in the 1970s when it caused a young boy, David Vetter, to live for 12 years in a plastic, germ-free bubble.

Felix was first transported to London, Ont., where he spent five months in a sterilized room. His parents, Kathleen and Ben Quiring, essentially lived at the hospital, visiting Felix while wearing rubber gloves, gowns and face masks.

"A part of me didn't think we'd ever be taking him home," Kathleen said.

Kathleen Quiring holds her son Felix during his time in sanitary isolation. Felix was born with severe combined immunodeficiency, which left him vulnerable to any germ or virus.

Early detection essential

Felix was only able to get treatment for his genetic disorder because Ontario is one of the few places in the world that conducts early screening through heel prick tests, said Dr. Marina Salvadori, who works at London Health Sciences Centre.

Before the early screening, Salvadori had several patients die because of the same disorder. That all changed with Felix.

"Not many places screen for this gene defect," she said. "You have to know about it, because that's really the only way to find it in time to do this life-saving therapy."

In London, Felix was treated in a sterilized room until he was strong enough to go home in April 2015. He still had to be isolated in a sterilized bedroom and could not have many visitors.

By July, the family was off to Los Angeles for a new gene therapy. The clinical trial has, so far, only treated 15 children, according to Salvadori. Felix was No. 14.

Doctors harvested his bone marrow and treated it with the enzymes needed to rebuild his immune system. They then put the bone marrow back into his body.

"For me, it's a real miracle," Salvadori said. "I've seen several of these patients actually die, because there was nothing we could do to help them."

'Pretty normal now'

A clinical trial has improved the immune system of Felix Quiring, who for more than a year was unable to be held by his parents without rubber gloves. (Kathleen Quiring)

By Christmas, Felix was able to have more visitors at home. Now he's able to go to the park or the grocery store, all those simple things that were impossible a year ago. He's even fought off two colds since the treatment.

Kathleen and Ben spent a year unable to touch their child's skin, unable to press their lips against his. That's all changed, mom says, laying a smattering of kisses on Felix's face.

"We had to go a year without kissing him, so when that was finally something we were able to do, it's just something I never take for granted," Kathleen said.

Felix now has an immune system close to that of any normal boy his age. His parents still avoid bringing him to areas with a large number of children, in order to keep him from some larger viruses, like chicken pox.

But he's certainly come a long way in his recovery.

"Over the course of about a year, his immune system has become normal again," Salvadori said. "He's not 100 per cent normal yet, but he's pretty close.

Felix is expected to have a fully restored immune system in the coming months. In a few weeks, he'll receive his first vaccination.

"That's usually a pretty big step for children who've gone through these things," Kathleen said. "Once he's fully vaccinated, we think he should be able to do whatever any other kid his age can do."

Kathleen has written extensively about her family's experience on her blog, Becoming Peculiar. That process helped her cope, particularly in the beginning.

"It's very difficult to adjust to having to parent so differently from what I had in mind," she said.