There are 30 million blood transfusions every year in the United States; 107 million worldwide. Due to its universal acceptance, Type O negative is the most highly sought-after blood type. Only about 7% of the population has O negative blood, and its rarity makes it a fairly hot commodity. However, it looks like there will soon be a viable alternative, as blood created from stem cells is nearly ready for human clinical trials. The announcement comes from Marc Turner.

The process involves induced pluripotent stem cells (iPSCs), which are adult cells that have been forced back into stem cell state. They were then directed to differentiate into blood cells. “Although similar research has been conducted elsewhere,” Turner stated, “this is the first time anybody has manufactured blood to the appropriate quality and safety standards for transfusion into a human being.”

Human trials are expected to begin in late 2016 or early in 2017. The first phase of the trial will utilize a small group of people who suffer from Thalassemia. This is an inherited disorder in which the hemoglobin cells are not properly formed, reducing the blood cell’s ability to transport oxygen. Routine blood transfusions are a common form of treatment for Thalassemia. Those selected for the clinical trial will be closely monitored after the blood has been transfused.

The implications of making this technique commonplace are obviously very important. A virtually unlimited supply of universally accepted blood, guaranteed to be free of disease. Not only will this address the blood needs of developed countries, but it could also help those living in areas who do not have blood banks with screened blood available.

Of course, nothing is without its challenges, so don’t cancel your appointment to donate blood just yet. First and foremost, human clinical trials can take years. Considering we may be about three years out before they even start testing with humans, it will take a long time to ensure that the transfusions are safe and effective.

Additionally, scaling up the process to make an adequate supply of blood is also proving to be tricky. Each unit of blood contains at least a trillion blood cells, and manufacturing the millions of units needed isn’t as simple as just making a larger batch of stem cells in one batch.

Image credit: Andrew Mason. Used in accordance with CC by 2.0