Thanks. When I got them, they were believed to grant permanent immunity, just like successfully fighting off the virus.

A study in the Annals of Internal Medicinefound that after 15 years, 84% of participants still had protective antibodies 15 years after receiving the vaccine series. Three participants became infected with hepatitis B 10 to 15 years after vaccination. (Which sort of demolishes my theory that infection might just act like a booster.)

So far though, in the US, there doesn't appear to be any recommendation for booster shots or even periodic titers for health care workers (CDC recommendations) or the general population (CDC recommendations).

Guess they'd do a titer or give me a booster if I ever got exposed.