Red Cross Urges Blood Donations Amid O Negative Shortage

The Belgian Red Cross (Rode Kruis-Vlaanderen) has issued an urgent appeal for blood donors, warning that stocks of O negative and B negative blood types have fallen to critically low levels. “Every patient can receive blood from donors with O negative, their blood is therefore extra valuable,” said Managing Director Philippe Vandekerckhove, as reported by VRT NWS. “Who has O negative or B negative can now really make a big difference.”

The Summer Dip

The shortage stems from an annual phenomenon known as the “summer dip” (zomerdip), during which blood donor numbers typically drop by 10 to 15 percent in July and August. According to Vandekerckhove, speaking to HLN, “On average, over the past years we see the number of donors drop by 10 to 15 percent during the summer vacation, which naturally has an impact on the blood supply.”

The decline has multiple causes. Many regular donors are on vacation and postpone their donations, while others are temporarily excluded after traveling to certain destinations with health risks, such as malaria-endemic regions. Meanwhile, hospitals continue to require blood for surgeries, childbirths, and cancer treatments throughout the summer. Blood’s limited shelf life of 35 to 42 days means supplies must be constantly replenished, making seasonal dips particularly challenging.

Why O Negative Matters

While nearly all blood groups are under pressure, the shortages of O negative and B negative are of greatest concern. O negative is known as the “universal donor” because it lacks A, B, and RhD antigens, making it compatible with any patient in emergency situations where blood type matching has not yet been performed. De Morgen reported Vandekerckhove stating, “That O negative is also so low is not a good thing. It is the universal donor: every patient can get blood from donors with O negative.”

The organization emphasized that this shortage poses a direct risk to emergency medical services across Flanders. In urgent medical situations where there is no time to determine a patient’s blood type, O negative is the default choice for transfusions, making its scarcity a critical concern.

How to Donate

Rode Kruis-Vlaanderen operates 16 permanent donor centers in Flanders alongside numerous local blood drives that continue throughout the summer. Potential donors can make an appointment through the organization’s website or by calling the free number 0800 777 00. Vandekerckhove advises donors to first complete an online questionnaire to check their eligibility before visiting a center.

All Blood Types Welcome

Despite the critical focus on O negative and B negative, the Red Cross stresses that donors of all blood types are urgently needed. “Every blood donation helps restore the supply and give patients the care they need,” Vandekerckhove said. Donors with other blood groups are also very welcome, as every donation contributes to stabilizing the overall blood supply.

The organization has issued similar appeals in previous years, including in May 2026 and during summer dips in 2019 and 2021, highlighting the persistent structural challenge of maintaining adequate blood supplies during vacation periods. With the healthcare system continuing to operate at full capacity throughout the summer, the recurring nature of these shortages points to a need for sustained donor engagement beyond seasonal peaks.

Looking Ahead

With the summer vacation period still in full swing, the shortage could persist for several more weeks unless donors respond quickly. The Red Cross is calling on eligible donors—particularly those with O negative and B negative blood types—to come forward in the coming days. As Vandekerckhove emphasized, the situation underscores the ongoing vulnerability of the voluntary blood donation system to seasonal fluctuations, making every donation count in ensuring that Flemish hospitals can continue to provide life-saving care to those who need it most.