Inclusion Criteria:

- Signed Informed Consent

- Women, ≥ 18 years of age

- Histologically documented, HER-2-positive breast cancer without metastatic disease.
Hormone receptor (ER/PR) status may be either positive or negative. HER-2
(+) status may be determined by one of the following measurements:

- Immunohistochemistry 3+ or FISH/CISH+ (HER-2 gene signal to centromere 17 signal >
2). NOTE: HER-2 assessment may have been on initial diagnosis and need not be
repeated.

- Patients should be assessed as having no evidence of disease (NED) at the end of
adjuvant chemotherapy. In addition, these patients must have a clinical evaluation
and lab work as standard of care disease assessment without evidence of recurrence
within 28 days of the first planned dose of MVA-BN®-HER2.

- Completed adjuvant and/or neoadjuvant chemotherapy for breast cancer at least 3
months previously (measured from the date of the last dose of chemotherapy) and prior
to the first planned dose of MVA-BN®-HER2).

- ECOG Performance Score of 0, 1.

- Predicted life expectancy ≥ 12 months

- Left ventricular ejection fraction (LVEF) by ECHO ≥ LLN as defined by institutional
standards

- Women of childbearing potential must:

- have a negative serum or urine pregnancy test, and

- must agree to use a medically acceptable barrier and/or chemical method of
contraception throughout the study treatment period and for 28 days after the
last dose of MVA-BN®-HER2.

- No significant cardiac, bone marrow dysfunction, or coagulopathy (defined as no Grade
3 or greater AE according to NCI CTCAE v 3.0). No significant hepatic or renal
dysfunction (defined as no Grade 2 or greater AE according to NCI CTCAE v 3.0.
Patients with a known history of a CLINICALLY NON-SIGNIFICANT laboratory parameter
may be eligible for inclusion provided an exemption is granted by the study Medical
Monitor prior to enrollment.

- A negative virology screen for HIV, HBsAg, and HCV

Exclusion Criteria:

- Congestive heart failure (NYHA Class III or IV), unstable angina, or cardiovascular
disease such as stroke or myocardial infarction (current or within the past 6 months)

- History of cardiac toxicity secondary to chemotherapy or Herceptin immunotherapy
(LVEF decline of 15% or greater from baseline)

- History of prior malignancies other than breast cancer within the past 5 years,
excluding basal or squamous cell carcinoma of the skin or carcinoma in situ of the
cervix

- Any breast cancer metastases beyond the lymph nodes

- Known allergy to eggs, egg products, or aminoglycoside antibiotics, e.g., gentamicin
or tobramycin

- Chronic administration (defined as 6 or more consecutive days of use) of systemic
corticosteroids within 14 days of the first planned dose of MVA-BN®-HER2. Limited use
of inhaled steroids, nasal sprays, eye drops, and topical creams for small body areas
is allowed.

- History of or active autoimmune disease. Persons with vitiligo or thyroid disease
taking thyroid replacement hormones are not excluded.

- Prior solid organ or hematopoietic allogenic transplant(s)

- Prior use of hematopoietic growth factors (e.g., GM-CSF) within 14 days of the first
planned dose of MVA-BN®-HER2

- Receipt of an investigational agent within 28 days of the first planned dose of
MVA-BN®-HER2

- Prior "vaccine" therapy for breast cancer at any time

- Vaccination:

Live (attenuated) vaccine (e.g., FluMist®) Vaccination with a live vaccine within 28 days
of the first planned dose of MVA-BN®-HER2, or plans to receive a live vaccine within 28
days after the last dose of MVA-BN®-HER2 is not allowed Killed (inactivated) vaccine
(e.g.,PneumoVax®) Vaccination with a killed vaccine within 14 days of the first planned
dose of MVA-BN®-HER2, or plans to receive a killed vaccine within 14 ' days after the last
dose of MVA-BN®-HER2 is not allowed

- A maximum cumulative dose of prior doxorubicin > 360 mg/m2 or epirubicn > 720 mg/m2

- Radiation therapy within 14 days of the first planned dose of MVA-BN®-HER2 or plans
for radiation therapy after enrollment. Prior to initiating palliative radiation
during the treatment phase of the study, the Sponsor's medical monitor or designee
must be contacted.

- Pregnant, lactating, or nursing

- Any condition which, in the opinion of the investigator, would prevent full
participation in this trial or the long-term follow-up study, or would interfere with
the evaluation of the trial endpoints