A 51-year-old man with chronic hepatitis B (HBV) infection and a 4 cm hepatocellular carcinoma underwent liver transplantation (LT) 10 days ago. He was on entecavir for his chronic HBV infection. He had undetectable HBV DNA at the time of LT.

In addition to intravenous infusions of Hepatitis B immune globulin (HBIG) intra- and peri-operatively, which of the following is the best post-transplant management option?