This makes me insane. Like many in the comments here I’ve had this statement made to me by several patients, and it’s such an infuriating case of opinions made by people without any knowledge or understanding of how vaccines and blood transfusions work. Attempts to educate them are generally met with argument or unwillingness to acknowledge the science. The vaccine components are no longer detectable in a vaccine recipient after 30 days. And it’s generally primarily detected in lymphatic tissues (like lymph notes) or tissues with an active immune response. In circulating blood volume it is detectable for a shorter time, just a couple weeks. Most people when undergoing blood transfusions receive packed red blood cells. This is red blood cells that have been separated from plasma (which is where you might find viral antibodies or antigens, and would be present whether the antibodies were generated from a Covid infection in the past or a vaccine). Plasma transfusions, whole blood, or platelet transfusions are used for other less common indications related to immune disorders, clotting disorders, or massive transfusions for acute exsanguinating situations. Even if these products are used, the vaccine itself would not be present in the products unless donation occurred nearly immediately post vaccination. Adding additional screening for such a low risk, low yield finding only adds cost and time in an already slow and expensive health care system. If you have the luxury of time to designate a directed donor then great, go for it. I think it’s fine to care where blood you might receive came from. Testing for things that are actually dangerous is a routine part of the donation to transfusion process. But adding in unnecessary burdens to the system for this is unhelpful and unscientific. Legislators pushing this forward clearly care more about the politics than the facts. No real surprise there I guess.