Cancer patients with COVID-19 have a 30% higher mortality rate compared to the general population and are considered a high-risk group by the American Association for Cancer Research that should be given "high priority" during COVID-19 vaccine administration. Although studies have suggested that vaccination during active treatment with chemo and/or radiation therapy provides suboptimal antibody response, the studies were underpowered and heterogeneous thus putting this conclusion into question. We need data in cancer patients on immunosuppressive chemotherapy at the time of COVID vaccination to understand how immune responses compare to healthy controls and cancer patients not on immunosuppressive therapy.

Inclusion Criteria:

• Participants must meet all of the following inclusion criteria to be eligible for enrollment:

  1. Willing and able to provide written informed consent for the trial.
  2. Male or female participants >18 years of age on the day of signing informed consent.
  3. a. Participants (>18 years) with gastrointestinal (gastroesophageal, pancreatic, small bowel, colon, anal) solid tumors, breast, or prostate cancers who received myelosuppressive chemotherapy within 60 days prior to initial or booster COVID vaccination, or who started on chemotherapy within 60 days after the initial or booster COVID vaccination; or b. Adult participants (>18 years) not receiving chemotherapy at the time of initial or booster COVID vaccination, but who were on non-immunosuppressive treatments (endocrine therapy, treatment with tyrosine kinase inhibitor or antiHER-2 therapy); or c. Adult participants > 18 years either: (i) with no history of cancer or (ii) prior history of non-metastatic solid cancer invasive cancer treated with a curative intent, without evidence of disease recurrence, and >12 months from completion of chemotherapy or radiation.
  4. a. Participants in groups A and B who have a planned COVID vaccination within the next 90 days of study enrollment with any FDA approved vaccine, or previous COVID vaccination within 90 days from study enrollment are eligible provided they meet all other above eligibility criteria; or b. Participants in group C who have planned COVID vaccination within the next 90 days of study enrollment with any FDA approved vaccine; or previous COVID vaccination within six months from study enrollment are eligible provided they meet all other above eligibility criteria

Exclusion Criteria:

• Participants will be considered ineligible for enrollment with the following criteria:

  1. Participants currently on immunotherapy
  2. Participants with documented COVID 19 infection within < 6 months from study enrollment
  3. Prior history of autoimmune disorder and are currently on immunosuppressive therapy or have received immunosuppressive therapy within the last 6-12 months prior to enrollment
  4. No planned and no prior COVID vaccination

Group A will consist of 50 participants with a diagnosis of one of the following cancers: breast, colorectal, or prostate cancers who received myelosuppressive cytotoxic chemotherapy at the time of COVID vaccination, or who received chemotherapy within 30 days prior to the initial or booster vaccination, or who started on chemotherapy within 30 days after the initial or booster COVID vaccination. Group B will consist of 25 participants with a diagnosis of breast, colorectal, or prostate cancers who are on non-myelosuppressive treatment including endocrine therapy, tyrosine kinase inhibitor or anti-HER 2 therapy. Group C will consist of 25 age matched adult participants with no prior history of cancer or prior history of non-metastatic solid cancer invasive cancer treated with a curative intent, without evidence of disease recurrence, and >12 months from completion of chemotherapy or radiation.