Oliver Moody , Berlin Courtesy The Times

On the morning of their wedding Ozlem Tureci and her groom Ugur Sahin turned up to the laboratory as usual. After a brief interlude at the register office they put their white coats back on and returned to work.

It was this tranquil single-mindedness that made Dr Tureci, 53, and Dr Sahin, 55, paper billionaires and two of the most interesting figures in modern oncology.

Now it has put the German-Turkish couple on the brink of claiming the world’s first demonstrably effective coronavirus vaccine and may bolster their fortune to more than £3 billion.

Ozlem Tureci and Ugur Sahin were pioneers in the treatment of cancer

Both were four years old when their parents moved from Turkey to settle in Germany as part of the first Gastarbeiter, or guest worker generation.

Yet they came from quite different social backgrounds. Dr Sahin, who was born in Iskenderun, near the Syrian border, was the son of a Cologne car factory worker and picked up his enthusiasm for medicine from popular science books.

Dr Tureci, an Istanbul surgeon’s daughter who describes herself as a Prussian Turk, grew up with medicine in her blood and watched her father operating on patients while she was still a child.

The pair met at Saarland University Hospital in Homburg, a few miles from the French border. They soon found themselves at the cutting edge of cancer medicine, working out how to train the immune system to spot and eradicate tumours itself.

At the time the notion of treating cancer with anything other than surgery, radiation and chemotherapy seemed outlandish. It took a long time to become accepted that the immune system is a very potent tool to fight cancer,” Dr Tureci said in 2017, a year before three of the field’s pioneers were awarded the Nobel prize for medicine.

In 2001, the year before they married, they founded their first joint company. Ganymed Pharmaceuticals specialised in what was at the time a relatively new and exciting class of drugs known as monoclonal antibodies, essentially mass-produced and harmless tags that teach the body’s defences to recognise cancer. The firm was eventually sold for €1.3 billion in what was the biggest biotechnology deal in German history.

Their next venture made them celebrities, at least by the standards of experimental oncology.SPONSOREDTired of 2020 waylaying your plans? Read thisThis is what companies could have done better during lockdown

Until last year Biontech, founded in 2008 and based in Mainz, was best known for building personalised cancer vaccines” out of messenger RNA (mRNA), which carries genetic instructions for cells. Essentially, the vaccines prompt the body to mobilise against cancer the way it would against a virus.

Fortunately for mankind, this strategy would also be theoretically quite handy against the coronavirus.

In January Dr Sahin read an article in The Lancet about an outbreak of a novel infectious disease in Wuhan. He instantly spotted the danger. Experts experienced with previous outbreaks said this will come and go,” he told the Financial Times months later. I said, ‘No, this time it is different.’ ”

Within days of the pandemic’s arrival in Germany, Dr Tureci, Dr Sahin and their colleagues began adapting their technology to Covid-19. Biontech was placed on a war footing” for what was known internally as the speed of light” project because of the intense time pressure it was under.

Pfizer, an American pharmaceutical company, soon piled in with funding and the company’s share price tripled over the course of the summer. This increased the couple’s fortune to roughly €2.4 billion (£2.16 billion) by September, according to the Welt am Sonntag newspaper, which ranked the couple at 85th on its national rich list. Their young company is now worth more than €20 billion, making it more valuable than Porsche and Deutsche Bank.

Biontech’s mRNA-based approach is technically ambitious compared with the methods of other groups including the Oxford team, who have taken the more tried-and-tested path of adapting a virus that already exists in nature.

The manufacturing process, in which the mRNA is bundled into a microscopic blob of fat, is well suited to mass production and the company has said that it aims to have 100 million doses waiting to go by the end of the year. But the colossal scales involved are uncharted territory for the technique.

If the experiment pays off, it will not just be good news in the battle against coronavirus, as well as a vindication and a fabulously lucrative payday — on paper at least — for the scientists. It will also be proof of a concept for a promising new way of warding off a whole menagerie of diseases from HIV to melanoma through the body’s own fortifications.

In keeping with the customs of the German super-rich, Dr Sahin and Dr Tureci have maintained relatively modest public profiles.

Investors well acquainted with the couple say that they remain driven by the prospect of medical advances rather than money.

Dr Sahin still commutes to Biontech’s modern office block near the west bank of the Rhine by bicycle and retains his professorship and the chairmanship of experimental oncology at University Hospital Mainz.

He is said to avoid checking the company’s share price. Had he broken with his habit and looked at it yesterday he would have seen it rise by as much as a quarter in a matter of hours.