It's lifetime protection. Once your body produces these antibodies, it will remember how to produce them again should the virus gets into your body (there's a medical term for this but can't think of it at the moment) - this is what my doctor told me.
A booster doesn't hurt, so if you want, go get one.
thank you for the answer, yes i had a response to the vaccine. Is it a lifetime protection or does it need to get boosted?