A peptide vaccine containing four immunogenic epitopes derived from the tumor-associated antigen (TAA) human epidermal growth factor receptor 2 (HER2; HER-2; ErbB2; Neu), with potential immunomodulating and antineoplastic activities. Upon intradermal administration, multi-epitope HER2 peptide vaccine H2NVAC may induce a helper T-cell mediated immune response against HER2-overexpressing tumor cells. This may result in long-term immunopotentiation against HER2-expressing tumor cells by increasing the helper T-cell response. HER2, a tyrosine kinase receptor for epidermal growth factor (EGF), is overexpressed in various cancer cell types.