When a compatible bone marrow donor is found for someone in need, it must reach them in fewer than 48 hours — no mean feat if they are on the other side of the world.
The COVID-19 crisis bought the planet spinning to a halt, grounding planes, yet it has failed to stop the process of stem cell delivery.
Transplants can be a matter of life and death for those with a blood disease so transplant centres have been forced to take decisive action during the pandemic.
The donations are no longer transported fresh but are cryogenically frozen in anticipation of longer delivery times.
Relays of couriers were organised at borders to move the precious bone marrow, while the crew members of planes were asked to escort the cooler bags to their destinations.
Some of the couriers have not been home for months, flying from one end of the globe to the other and sleeping in airport lounges.
In Spain, the airport civil guard facilitated one exchange between transporters who were unable to meet and in another, military planes collected stem cells from Turkey to save a child in Rome.
Nonetheless, the impact of COVID-19 has been felt in the sector.
Volunteers on donor registers have practically halved in Europe during 2020 and when looking at the situation in the EU's largest countries, everywhere tells the same story.
Compared to last year, the new donors recorded in Italy were down 49%, 37% in Spain and 40% in Germany, while France is hoping to sign up 58% of the people it did in 2019.
In the UK, the situation is far from rosy; in Leeds, for example, 50 people have registered so far in November compared to 950 the previous year.
In Italy, the Bone Marrow Donors Association (ADMO) was forced to stop events aimed at raising awareness for the cause in schools and universities, as well as meetings in sports centres and town squares. The same happened in France.
In France and Spain, during the first wave of the coronavirus, new registrations were suspended for four months, meanwhile, in Germany, events dedicated to blood donations were put on standby due to a ban on gatherings.
Luckily, however, the decline in the number of new registrations has not caused a reduction in the number of donations and there have been very few occasions when a life-saving transplant has been postponed or cancelled.
Why does Germany tally so many donor registrations?
Some countries, like Germany, managed to register 827,000 new donors in 2019, while others, such as Italy and Spain - that have fragmented regional healthcare systems - managed to log 49,000 and 36,000 new names respectively.
But even in some countries where the healthcare system is public and centralised, like in France, they still haven't managed to match the German numbers, with just 27,000 signing up.
In Germany a registration costs between €35 and €45, while in Italy this figure rises to €250 per sample and that's excluding the costs of healthcare staff.
Why are there such marked differences between European countries? In Italy, NGOs like ADMO, as well as Adoces and Adisco, are responsible for registering and taking samples. The only register in Italy is found in Genoa.
Add to this limits on the number of registrations that are funded by the state, as well as the high cost of the activity that precedes the collection of the kits, such as those of promotion, which Rome is not able to finance.
Germany is home to the main pool of donors in Europe, where a tenth of the eligible population (between 18 and 55 years) is on the register and is able to export 70% of bone marrow harvested from its citizens to help patients outside of Germany.
The German system relies on 26 independent donor centres, which are mostly private or connected to universities or transfusion centres.
Each is in charge of its own funding and recruitment strategies, has no relationship with local authorities and is able to reinvest the money raised through private donations in registering new donors.
In France, the 29 centres that recruit volunteers are linked to transplant centres, often encapsulated in structures that facilitate blood donation or public hospitals.
Compared to Germany, says Dr Evelyne Marry, director of blood marrow collection and transplant at the French Biomedicine Agency, "we made a choice on profiles based on quality, rather than quantity, focusing on young people (the younger the donor, the higher the chances of successful transplantation) and different geographical areas".
The strategy is decided by Paris, while in the German Länder there is no central coordination.
Then there Spain, which since 2018 has decided to focus on donors under 40 — a choice that has inevitably reduced the number of registrations compared to previous years.
Here the system is entirely public; the numerous Spanish centres are governed by the country's 17 autonomous communities, but each follows its own strategy for registering new donors.
"Nowhere, except in Galicia, do we use mouth swabs. Blood samples are used everywhere. Why? For so many reasons, even if none of them has anything to do with science," said the Dr Enric Carreras, director of the Spanish bone marrow donor programme, managed by the Josep Carreras Foundation.
Carreras said no communication campaigns have been carried out since the beginning of the pandemic by his private non-profit foundation, which manages registrations for the state.
"For now, people are not thinking about donations, but they are worried about saving themselves and not getting infected," he said.
"This year there has been some decline in donations and transplants but not because of a lack of donors, but because hospitals have had to cancel planned operations due to a lack of beds," according to Carreras. "If there is no bed in the ICU, in case of post-transplant complications, the surgery must be cancelled."
During the first wave, "those from Girona could not go to Barcelona to make the donation," he said, but added the foundation had found solutions to the problems posed by the pandemic "in one way or another".
A donor hub in the Netherlands
All the donors registered in the various countries of the world end up in the WMDA, based in the Netherlands, a sort of world database that brings together 135 interconnected sources and registers. It has over 37 million potential donors.
"Thirty years ago, before the internet, it was basically a huge telephone directory with the names of potential donors," says Joannis Mytilineos, director of the German register ZKRD.
Whenever a hospital makes a request, a search is activated globally — the marrow is sold by one transplant centre and purchased by another, with the national registry acting as an intermediary.
Countries set their own prices; the cost of one unit from Germany is between 14,000 and 17,000 euros. A marrow that comes from the USA, on the other hand, can cost as much as 30,000 dollars.
About 37% of stem cells transplanted worldwide from donors other than family members come from Germany.
Mytilineos, who has Greek origins, says German donors are compatible with so many people abroad "because of our migratory past, which DNA keeps track of".
Obviously, it is cheaper for national health systems to find donors at home and not just for greater genetic compatibility between subjects. "A transplant from Spain to Spain costs € 4,500, less than a third of the marrow purchased from abroad," said Carreras.
But Marry points out: "We are not competing between registers. Each country has its own rules, there are those who have public funding, those who are private, but the philosophy of registers around the world is to raise awareness and the machine of international solidarity work."
Bone marrow donors are "an international community, the inefficiency of one country is overcome by other countries, but every country strives for the best," concludes Mytilineos.
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