The frequency of E75-specific CD8+ T cells will be determined as the percentage of cells that are alive, lineage-, CD3+ CD8+ and E75-dextramer+. 4.4.7 Local reaction Patients will be assessed for evidence of in vivo immunologic response by evaluation of the injection site 48-72 hours after each inoculation. The injection site reaction will be measured using the sensitive ball point pen method if the patient returns to the study site. A digital photograph of the local reaction may be taken to document the reaction and for future reporting purposes. It will in no way be visually identifiable as that patient. Photographs will be labeled with the patient’s study number and will not include the face or distinguishing birthmarks or tattoos. They will be electronically stored on a password protected computer in a locked office in the vaccine or clinical laboratory facility at each site. Per 30 Protocol: 2014-0443 Version 2.1 Version Date: 11 April 2016 FDA regulations, each patient’s photograph will be kept for two years after submission of a New Drug Application (NDA) and then destroyed. If the patient does not return to the study site, they will be contacted by phone 48-72 hours after inoculation for questioning regarding the reaction at the injection sites. 4.4.8 DTH reaction Regardless of randomization, a pre--inoculation series DTH response will be assessed of all patients with 100 mcg of nelipepimut-S (without GM-CSF) injected intradermally at a site on the back or anterior thigh (opposite side from the vaccination site). A post-inoculation series DTH response will be assessed one month ± 1 week after completion of the PVS. The DTH reaction will be measured at 48-72 hours using the sensitive ball point pen method and compared between pre-inoculation and post-inoculation time points. Additionally, a DTH responses will be assessed 1 month ± 1 week after the fourth booster. The low dose of peptide used in the DTH test is not expected to induce a long-term immune response in control patients; however, any response that is induced is expected to be transitory in nature. A digital photograph of the local reaction will be taken to document the reaction and for future reporting purposes.