Do I have to get the Hep B again?

If you have already gotten the series you do NOT need to get them again. You should have gotten 3 of them. My kids got them when they were babies, but they were not offered when I was a kid so I get them now. Yeah Me!

This isn't necessarily true. When the vaccine first came out, people were administering it in the gluteus, and it turned out later that it isn't absorbed well from there and lots of people didn't develop immunity. Also, like any other vaccine, it just doesn't work for some (a few) people.

If your antibody titer level isn't high enough, you haven't developed immunity and the series could need to be repeated (that's a decision that would need to be made with your PCP). I'm one of the "early" people who had to have a second round, given in my arm. I didn't mind; in fact, I was v. appreciative that my new employer bothered to check my titer and found that I wasn't immune -- I had been assuming, for several years, that I was, since I'd had the vaccine. After the second round, I did develop immunity (we checked! :))

Also, we don't really know yet how long the immunity will last -- there's a good chance that, at some point many years down the round, it will just "wear off."

If there's any question, you can always get your titer checked (again, that's a decision to made with your PCP).

And if necessary, getting the series of shots again is a lot less troublesome than getting Hep B!.

Definitely!!

And this conversation reminds me (hadn't thought of this in years :)) of the comment the employee health physician for my new employer (the one that ate the bill for repeating the Hep B series) made -- the Hep B vaccine isn't just the three shots; you're not really done until you've checked your titer and are sure that you've developed immunity.