The present invention relates to a polypeptide comprising (a) a first set of six complementarity determining regions (CDRs) configured to bind a first antigen; and (b) (ba) a second set of six CDRs configured to bind a second antigen; or (bb) a ligand capable of binding to a second antigen; wherein (i) said first antigen is selected from Hepatitis B virus (HBV) small surface antigen; HBV medium surface antigen; and HBV large surface antigen; and (ii) said second antigen is selected from surface antigens presented by immune effector cells such as natural killer (NK) cells and cytotoxic T lymphocytes (CTLs). Also provided are compositions for use in a method of treating or preventing HBV infection and/or a condition caused by said HBV infection, said condition caused by said HBV infection being selected from liver cirrhosis and hepatocellular carcinoma.