In my case I was specially included for giving blood to premature babies, because I did not have a particular antibody and, therefore could not be a carrier of a certain disease. I am O-Negative and a universal donor. I gave up that volunteer activity when I moved but had made 152 whole blood donations by then.
Heck... First time I went to give blood they rejected me because I had dental work a month prior. But now;
“Are you a junkie homo that has unprotected gay sex in Haiti?”
“Yes”
“Well give us all the blood you want.”
I am B neg and always in demand