How about that...a number I had never seen before regarding exchange transfusions. From Wiki
The first treatment for Rh disease was an exchange transfusion , which was invented by Dr. Alexander S. Wiener . That procedure was further refined by Dr, Harry Wallerstein, [4] a transfusionist. Although the most effective method of treating the problem at the time, it was only partially ameliorative in cases where damage to the neonate had already been done. Children with severe motor damage and/or retardation could result. However, it is estimated that in the two decades it was used approximately 200,000 lives were saved, and the great majority were not brain damaged.
So 200k lives were saved by blood transfusions, just for this one disease. The only modern cure from Rh disease comes from plasma....striking. Looks like I need to go out and donate.