Merkel cell carcinoma (MCC) is a very rare skin cancer, but it is the second most common cause of skin cancer death after melanoma. Merkel cells are found in the top layer of the skin and are very close to the nerve endings that receive the sensation of touch. When Merkel cells grow out-of-control a lesion usually appears as a single painless lump on skin. MCC starts most often in areas of skin exposed to the sun, especially the head and neck, as well as the arms, legs, and trunk. MCC usually grows quickly and spreads at an early stage. It usually spreads first to nearby lymph nodes and then may spread to lymph nodes or skin in distant parts of the body such as lungs, brain, bones, or other organs. This Clinical Trial provides a vaccine that is injected directly into a carcinoma lesion on the skin on (up to) three occasions, which triggers the immune system to attack the cancer cells.