The present invention relates to tumor immunotherapy, in particular to tumor vaccination, using chimeric proteins comprising all or a portion of a hepatitis B virus core antigen protein and an amino acid sequence comprising an epitope derived from the extracellular portion of a tumor-associated antigen. In particular, the present invention provides virus-like particles comprising said chimeric proteins, which are useful for eliciting a humoral immune response in a subject against the tumor-associated antigen, in particular against cells carrying said tumor-associated antigen on their surface, wherein the tumor-associated antigen is a self-protein in said subject.