A few years ago, I tried to donate blood but couldn’t because they found Hepatitis B antibodies (indicating I’d contracted the disease.) I received the awful letter pretty much telling me I’d been blacklisted forever for blood donation. Now, I’m applying to nursing schools and have to prove that I’m either a) immune to it or b) have had the vaccine series. Thinking that I’m immune to it, I had a blood test in order to obtain official proof of my immunity but the test came back negative. What gives?