As a baby I lived in a protective 'bubble' but after pioneering gene therapy I beat Covid twice

After being born without a functioning immune system, Rhys Evans faced the prospect of living the rest of his life in a protective "bubble", unable to see the outside world.

But after receiving pioneering gene therapy at London's Great Ormond Street Hospital, he has gone on to live a normal life, working as stage crew at Butlin's in Minehead, Somerset.

Now 26, he said it is incredible many others have been saved after he was the "guinea pig" for the treatment 25 years ago.

A new gene inserted into his bone marrow helped him to develop an immune system, and Prof Adrian Thrasher, who pioneered the therapy and operated on him, said more than 130 people had received the treatment since 2001.

"I was the guinea pig, and because the treatment worked, they could treat many others," Evans said.

Originally from Nelson, Caerphilly county, he was born with x-linked severe combined immunodeficiency (XSCID), which left him at constant risk of life-threatening infections.

He believes it could have meant he faced the rest of his life strapped in a chair or in a bubble "not being able to see the outside world".

"I would feel like I would be in prison," he said.

But the treatment gave him an immune system strong enough to since overcome Covid twice and he believes he can now fight most viruses.

"I've been able to live a normal life – go to school and university, see friends and plan for the future, things my family once couldn't take for granted," he added.

SCID is the name for a group of rare inherited disorders that cause major abnormalities of the immune system.

The first signs are babies start suffering infections more frequently than other infants, and coughs and colds seem more severe.

They may also feed poorly, have chronic diarrhoea, skin rashes and fail to gain weight normally.

Before modern medical interventions, most infants with SCID did not survive past their first birthday.

There are no UK-wide figures, but it is estimated to affect one in every 40,000 babies in England, or 14 a year, according to Great Ormond Street.

Today, doctors understand much more about SCID, with treatment available to reduce the risk of serious infection or to cure the disorder, according to the NHS.

But back in 2001, the only options available to Evans and his parents were chemotherapy or an "incredibly difficult" bone marrow transplant.

"Essentially my immune system wasn't functioning properly – I was so weak," he said.

He also lost weight, was vomiting, had diarrhoea and twice caught pneumonia.

One of the best-known cases of SCID is that of David Vetter – nicknamed "Bubble Boy" – whose illness when he was born in the US in 1971 made it impossible for him to engage with the world outside a plastic chamber.

Within seconds of his birth, he was placed in an isolation chamber, where he lived until the age of six when he was given a special plastic suit designed by Nasa, the US space agency.

He died aged 12 after a failed bone marrow transplant.

Evans was also separated in a "bubble", for which people "needed to be sterilised" before they could enter.

"The air was filtered - no infections, no viruses in the air," he said.

"And that was how it was until my parents signed a waiver saying they wanted this gene therapy."

The gene therapy had been worked on in a laboratory for 15 to 20 years, said Thrasher, from University College London.

He developed it alongside experts from Great Ormond Street, and added: "Eventually we felt we were ready to take that technology to patients, and Rhys was the first."

Thrasher said they were confident it would work as they had done a lot of research.

It involved taking 100ml of Evans' bone marrow, putting the new gene into it, then injecting the bone marrow back into his body.

"Then we waited - we didn't do anything else," Thrasher said.

"[Evans'] own bone marrow regenerated his immune system with the new gene in it."

Within weeks, Evans' immune system began to develop, and shortly after his second birthday he got the flu.

"That was a good test to see if [the treatment] had worked. I dealt with it OK and survived, so that was good news," Evans said.

Thanks to developments in gene therapy, today, many people who previously had a life expectancy of a few years are able to live fully active lives, according to Great Ormond Street.

Most patients treated with gene therapy trials at the children's hospital have had different forms of SCID, but they have also included those with leukaemia, spinal muscular atrophy and Leber's Congenital Amaurosis, an inherited disorder that causes children to lose their sight.

Two and a half decades after operating on Evans, Thrasher - who recently met his former patient at Great Ormond Street - said it was "fantastic" to see him doing well, adding there was pride among the team they had contributed to him living a healthy life.

Thrasher also praised Evans and his family, emphasising that the treatment had not been "sold" to them, but rather discussed as one option in a range of therapies available.

"It's a very difficult concept to explain to a layperson that you're going to put a new gene into a bone marrow of your child who is dying," he said.

"As a doctor, the most important thing for me is that he's healthy."

Similarly, Evans feels pride that the treatment he received more than two decades ago is still saving lives, saying it was "incredible to see how they've developed as people".

The only indications of the illness he had as a baby is the fact he has an antibiotic infusion once a week, as well as the warts that have developed on his hands.

Evans said he was "incredible grateful" to the doctors who pioneered the treatment and looked after him.

"They've essentially given me life."