A Feasibility Study Utilizing Immune Recall to Increase Response to Checkpoint Therapy

The purpose of this study is to determine the safety and feasibility of administering the Tetanus Diptheria Vaccine (Td) or Polio Boost Immunization (IPOL) to patients with metastatic melanoma who are receiving immune checkpoint inhibitor (IO) therapy per standard of care. Subjects will have the vaccine at cycle 4 of IO therapy and will have research blood and tissue samples collected prior to starting IO therapy, at cycle 4 prior to vaccine administration, and at 12-17 days post vaccine.