In this study, the investigators intend to assess the ability of the combination of Herceptin and NeuVax vaccine (HER2 protein E75 peptide administered with the immunoadjuvant GM-CSF) given in the adjuvant setting to prevent recurrences in NP (or NN if negative for both estrogen (ER) and progesterone (PR) receptors) breast cancer patients with tumors that express low (1+) or intermediate (2+) levels of HER2. Enrolled patients will be randomized to receive Herceptin and NeuVax vaccine or Herceptin with GM-CSF alone (no NeuVax vaccine). The safety of the combination therapy will be documented, specifically to ensure that no additive cardiac toxicity results from combination HER2-directed therapy. Efficacy will be documented by comparing the DFS and immunological responses between treatment groups.