A Vaccine Booster (GEO-CM04S1) for the Prevention of COVID-19 in Patients With Chronic Lymphocytic Leukemia

Inclusion Criteria: Documented informed consent of the participant and/or legally authorized representative Age: >= 18 years Eastern Cooperative Oncology Group (ECOG) =< 1 Histologically confirmed diagnosis of CLL according to World Health Organization (WHO) classification Prior COVID-19 Vaccination (2 or more Pfizer or Moderna) with last injection >= 3 months prior Fully recovered from the acute toxic effects (except alopecia) to =< Grade 1 to prior anti-cancer therapy White Blood Cells (WBC) >= 1,000/mm^3 (To be performed within 14 days prior to Day 1 of protocol therapy) Platelets >= 50,000/mm^3 (To be performed within 14 days prior to Day 1 of protocol therapy) Total bilirubin =< 1.5 X upper limit of normal (ULN) (unless has Gilbert's disease) (To be performed within 14 days prior to Day 1 of protocol therapy) Aspartate aminotransferase (AST) =< 2.5 x ULN (To be performed within 14 days prior to Day 1 of protocol therapy) Alanine transaminase (ALT) =< 2.5 x ULN (To be performed within 14 days prior to Day 1 of protocol therapy) Creatinine clearance <1.5 ULN (To be performed within 14 days prior to Day 1 of protocol therapy) Women of childbearing potential (WOCBP): negative urine or serum pregnancy test (To be performed within 14 days prior to Day 1 of protocol therapy) If the urine test is positive or cannot be confirmed as negative, a serum pregnancy test will be required Agreement by females and males of childbearing potential to use an effective method of birth control or abstain from heterosexual activity for the course of the study through at least 6 weeks after the last vaccine injection Childbearing potential defined as not being surgically sterilized (men and women) or have not been free from menses for > 1 year (women only) Exclusion Criteria: Known current SARS CoV-2 infection Prior Evusheld or other anti-SARS CoV-2 prophylaxis < 2 weeks prior Prior hematopoietic cell transplantation (HCT) or chimeric antigen receptor (CAR) T cell therapy within the previous year Systemic corticosteroids required for chronic conditions at doses > 0.5mg/kg/day prednisone equivalent within 7 days of enrollment Intensive cytotoxic therapies, T-cell depleting therapies, within 30 days of enrollment; however, patients with stable disease on maintenance therapies are allowed (See ConMeds for lists of acceptable and contraindicated therapies) Participants who have had a live vaccine =< 30 days prior to administration of any dose of study vaccine or subjects who are =< 2 weeks within administration of inactivated vaccines (e.g., influenza vaccine). Flu shots are allowed > 2 weeks before a study vaccine injection and > 2 weeks post study vaccine injection History of allergic reactions attributed to compounds of similar chemical or biologic composition to study agent (e.g., egg allergies) Active infection not controlled on appropriate therapy History of adverse event with a prior smallpox vaccination History of pericarditis or myocarditis Any MVA vaccine or poxvirus vaccine in the last 12 months Females only: Pregnant or breastfeeding Any other condition that would, in the Investigator's judgment, contraindicate the patient's participation in the clinical study due to safety concerns with clinical study procedures Prospective participants who, in the opinion of the investigator, may not be able to comply with all study procedures (including compliance issues related to feasibility/logistics)