Without Vicky Lawrence, Elliott Brock might never have signed up for the London Marathon. Without Elliott, Vicky would not have even made it to the startline.

The life-saving process actually began back in 2000 – the year Vicky was born. That is when Elliott – then a complete stranger – signed up for the bone marrow register.

In 2008, Vicky’s parents became concerned when their usually very active eight-year-old began to feel tired all the time.

When she was eventually diagnosed with aplastic anaemia – a condition where your body stops producing enough new blood cells – doctors told them that if she had not been brought in she would have died within a month.

That was the moment when Vicky and Elliott’s lives became intertwined. Elliott donated the bone marrow that kept Vicky alive and on Sunday the pair will run the marathon to raise money for Anthony Nolan, the charity that brought them together.

“It’s crazy to think back that 12, 13 years ago it wasn’t even looking like I was going to reach Christmas and here I am about to embark on 26 miles of running alongside the person who did save my life,” Vicky told BBC News.

Elliott says talking about Vicky still gives him “a lump in the throat”. Thanks to him, the now 21-year-old has packed plenty into the past 13 years and is currently in her fourth year of a medical degree in Newcastle.

“It’s amazing anyway to save someone’s life but also to see what Vicky has gone on to achieve – medical student, worked and travelled abroad, sportsperson, musician,” Elliott, now 42, told BBC Sport.

“She’s such a force of nature and to think what would have been within a few weeks if I hadn’t been on the register.”

‘It’s surreal. We are technically related’

After the transplant, which Elliott is keen to point out was “pain-free” for him, donors and recipients have to remain anonymous for two years but during that time Vicky’s parents could send updates on her condition.

They informed him that she had defied expectations to get home in time for Christmas, that her hair had started growing back and “the roar when she went back into the classroom was deafening”.

The families fell out of touch for a few years but at the age of 15 Vicky sent Elliott a letter and they decided to meet.

Vicky remembers that experience “being quite surreal”, adding: “Me and Elliott share the same blood. We are technically related.

“It’s a very odd feeling. It was surreal to have him sat in front of me – this person who saved my life. It was a lovely afternoon.”

‘There are going to be a lot of tears’

It was Vicky who convinced Elliott that they should run the marathon back in August 2019.

Like many of the 40,000 other runners, they have had a long wait to line up at the start in Greenwich after the mass participation race became a virtual one in 2020 because of Covid-19.

Elliott took on that virtual challenge near his home in Essex, and the father-of-two feels ready for the big day, saying he’s “managed to channel an inner Forrest Gump” during training.

He is also preparing mentally for what will be an emotionally charged event.

“My mum will be coming along,” he explained.

“She was cheering me on at the bedside when I did my transplant so the fact she is cheering me on 13 years later doing the marathon with the girl whose life that procedure saved is lovely.

“Just to see this girl so full of life, it’s a celebration of what Anthony Nolan achieves. It’s going to be very emotional.”

The pair plan to run the whole thing together and Vicky expects overwhelming feelings at the finish line.

“Running a marathon anyway is quite an emotional journey; running next to him is going to be amazing,” she says.

“Crossing the finish line, there are going to be a lot of tears. It shows how far I’ve come and that blood cancers and blood disorders aren’t the end of your life.

“It shows how important bone marrow transplants are. It’s going to feel amazing.”