Classed as an essential service, blood donation services across Europe have been urging donors to continue to travel to donation sites, even when their countries have implemented strict lockdown measures. There have been no reports of transmission of the virus through blood — which these services are at pains to point out.

However, in the U.K., blood donations were 15 percent lower than expected in mid-March. That resulted in the service having to reassure donors that it’s implementing extra safety measures.

In Bulgaria, the health ministry said that it’s “alarmed by the significant drop” in blood donors. And in Italy, after a drop in blood donations in some regions in early March, Italians were urged not to forget that patients still needed transfusions.

In Ireland, Deputy Chief Medical Officer Ronan Glynn took to Twitter to remind people that 3,000 blood donations were needed every week in the country. “The availability of this blood for transfusion is vital to the daily treatment of patients in our hospitals,” he said.

In the U.S., the American Red Cross has warned it faces a “severe blood shortage,” and that the shortage could impact patients in desperate need of blood. However, in Europe, the drop in donations has yet to hit patients.

As yet, there have been no reports of disruptions to the supply of blood or blood components, said Catherine Hartmann, executive director at the European Blood Alliance.

“Donations are down, but the demand from hospitals is also very much down, because hospitals are putting off elective surgery,” said Hartmann. “So basically everything that can be postponed is postponed at the moment in most countries.”

There is another factor at play here — altruism. The coronavirus may have ripped through the world, killing tens of thousands, but it has also seen acts of selflessness, such as the hundreds of thousands of Britons who volunteered to help their communities.

Urgent calls for blood donations are no exception. In Bulgaria, following the health ministry’s call, there were over 500 donations in just three days.

In Italy, the authorities’ plea was met with an “impressive” influx of donors. Most astoundingly, regions that have been brought to their knees by the virus have seen high numbers of donors, with hard-hit Lombardy having such a good response that it had 110 bags of blood to give to other areas.

But as coronavirus case numbers increase, say some experts, many more potential donors will be forced to self-isolate. And as Hartmann points out, regular donors are often older, and therefore more vulnerable to the virus, resulting in them staying at home rather than venturing out to a hospital to donate.

The European Centre for Disease Prevention and Control is also concerned. In its latest guidance, it warns that due to the nature of the coronavirus and its extensive spread, as well as previous experience from SARS and MERS, the virus could pose “a significant risk” to maintaining a sufficient and sustainable supply of substances such as blood and organs.

“Blood supply is particularly vulnerable as it requires daily frequent blood donations, and labile blood components have limited storage time and are in general irreplaceable,” said the ECDC.

Surgeries also cannot be postponed forever, said Hartmann. Looking forward longer-term, Hartmann said she “cannot predict anything” at this point.

“It will largely depend on how long the crisis lasts,” she added.

This article is part of POLITICO’s premium policy service: Pro Health Care. From drug pricing, EMA, vaccines, pharma and more, our specialized journalists keep you on top of the topics driving the health care policy agenda. Email [email protected] for a complimentary trial.