I got a Havrix vaccination before I went... and have to get the booster six months after the initial vaccine, so sometime this fall. Havrix covers one of the Hepatistis strains, not sure which one, but I had already been vaccinated in school for the other strain. Twinrix is recommended to cover both.
I came back from the DR with no issues what so ever though, so it probably isnt necessary as everyone else says!