Serologic Response to the SARS-CoV-2 (COVID-19) MRNA-1273 Vaccine in Select Subsets of Oncology Patients

Inclusion Criteria: * Subjects are between 50 and 75 years of age; * Have not had known or suspected infection with SARS-CoV-2 at any time; * Subjects must fall into one of the following subsets of cancer patients: * Localized prostate cancer on radiotherapy or have completed radiotherapy in the last three months * Prostate cancer on androgen-deprivation therapy for biochemical recurrence * Colon cancer on adjuvant chemotherapy for stage III disease * CLL on a BTK inhibitor as a first-line single agent for at least 3 months * Melanoma patients on adjuvant immunotherapy with PD-1 checkpoint inhibitors for at least 3 months * Have received both doses of SARS-CoV-2 mRNA-1273 vaccine with proof of vaccination or are scheduled to do so; * Have at least a one-year life expectancy; * Prior radiation therapy is allowed, as long as it was completed more than 6 months prior to vaccination Exclusion Criteria: * Subjects have a known hypersensitivity to a vaccine component; * Have had known or suspected infection with SARS-CoV-2 at any time; * Are organ transplant recipient on immunosuppression; * Had received or are scheduled to receive a live virus vaccine in the period from 4 weeks prior to Dose 1 through 28 days post second dose; * Had received or are scheduled to receive an inactivated vaccine in the period ranging from 7 days prior to Dose 1 through 7 days post second dose; * Received high-dose corticosteroids at any time after receiving the vaccine; * Are unable to give informed consent; * Are receiving treatment for CLL with another agent (such as rituximab) in addition to a BTK inhibitor