This disclosure provides a multimeric hepatitis B virus (HBV) protein binding molecule, e.g., a dimeric IgA or a pentameric or hexameric IgM binding molecule, comprising at least two bivalent binding units, or variants or fragments thereof, each comprising at least two antibody heavy chain constant regions or fragments thereof, wherein each heavy chain constant region or fragment thereof is associated with an HBV antigen binding domain. The disclosure also provides compositions comprising the multimeric binding molecules, polynucleotides encoding the multimeric binding molecules, and methods to make and use the multimeric binding molecules.
