Although costly and the blood given not completely screened, the unit of blood I received because of low Hgb hemoglobin 6.3 and low hematocrit saved my life.Was no longer dizzy, no tachycardia and more energy , shortness of breath just walking a very short distance. Although I have a long road ahead to feel good again. Pre vaccine,no pre-existing diseases, no drugs,excellent health, CBC normal. Sadly doctors will not believe the vaccine caused blood disorders. Truth is the Pfizer Covid bivalent booster where mRNA goes into every cell including blood cell needs to be looked at more seriously.