We propose to test the safety and bioactivity of an allogeneic GM-CSF-secreting breast cancer vaccine when given in a specifically timed sequence with Cyclophosphamide and Trastuzumab, two drugs commonly used to treat breast cancer. In this study the Cyclophosphamide is used at lower doses than usual to help the vaccine to activate the patient's immune system. Trastuzumab will be given at doses that are commonly used to treat breast cancer and it may also increase the immune response. The dose and scheduling of Cyclophosphamide and Trastuzumab used are based on testing the drugs with a GM-CSF-secreting vaccine in mice that get breast cancer, and are the ones that enabled the vaccine to induce the most potent anti-tumor immunity. The dose of vaccine cells is based on the safety of the same dose of a similar GM-CSF-secreting vaccine for pancreatic cancer. This breast cancer vaccine has also been given to people with breast cancer by itself, and with Cyclophosphamide and another chemotherapy drug, Doxorubicin. To date, people have had no vaccine-related serious side effects, but not enough people have received the vaccine to know if it treats breast cancer. The vaccine is experimental and has not been approved by the U.S. Food and Drug Administration (FDA). However, the FDA has permitted its use in this research study. This is the second study of this breast cancer vaccine and the first study to test this vaccine with Trastuzumab.