I took twinrix 2 years ago 2 doses, is it to late for the third one? and i was in shaghai 2 years after the doses, for one week, risky?

HepA/HepB vaccine: Twinrix can be administered on the same schedule as monovalent Hepatitis B vaccine: at 0- 1- and 6- months. In some circumstances, an accelerated dosing schedule of 0- 7- and 21-to 30- days followed by a booster at 12 months can be used and is believed to have similar efficacy as the traditional schedule. Would imagine taking it now would also have a booster effect.