Patient case (clinical description): The patient is a 38-year-old man with cough and body ache that started 3 days ago.  He had fever and chills at the beginning and has low grade fever at the time of visit. He feels tired and sleepy. His body ache and myalgia get better after using Tylenol. The PCR test for Covid is positive. His vital signs are within normal limits with a body temperature of 37.9 C. There is no lymphadenopathy or white exudates in the pharynx.

Patient's own account: I was feeling really sick the other day, to the point that I showed up at the doctor's office. I was coughing, and my body was hurting for 3 days. I had a fever and chills and felt tired and sleepy. I got better after using Tylenol. They did a PCR Covid test on me, and it was positive! My vitals were normal, and my temperature was 37.9 C. I had no swelling around my neck or white spots on the back of my throat.

Clinical trial: A Study of Hydroxychloroquine vs Placebo to Prevent COVID-19 Infection in Patients Receiving Radiotherapy

Eligibility criteria:
Inclusion Criteria:

          -  Age ≥ 18

          -  ECOG 0-3

          -  For patients who have not started radiation at the time of screening: patients are
             required to have a plan in place for a minimum of 10 radiation treatments with or
             without concurrent systemic therapy

          -  For patients who have already started radiation at the time of screening: patients
             must complete enrollment such that they are able to receive at least 10 radiation
             treatments with hydroxychloroquine.

          -  Disease Site

          -  Mandatory inclusion criteria:

          -  No COVID-19 symptoms within 14 days of enrollment:

               -  (Temp >38C in addition to sore throat, cough, wheezing, chest tightness,
                  shortness of breath, body aches, chills, diarrhea, and anosmia)

               -  If symptoms are present within 14 days of enrollment, patients with a negative
                  COVID-19 PCR or COVID-19 serology assay are eligible for inclusion.

          -  No close contact with confirmed COVID-19 person

          -  Close contact defined as:

               -  Within 6 feet for prolonged period

               -  Cohabitating

          -  Optional laboratory criteria (Recommended if available)

               -  Negative pre-treatment SARS-CoV-2 rapid antigen test result (within 1 week of
                  enrollment)

               -  Negative pre-treatment SARS-CoV-2 PCR test result (within 1 week of enrollment)
                  using MSKCC laboratory or outside laboratory assay

               -  Negative pre-treatment Standard Q COVID-19 IgM/IgG rapid serology result (within
                  1 week of enrollment)

               -  Blood serum for SARS-CoV-2 serology tests (being validated by MSKCC)

          -  Disease site meets following criteria:

               -  Head and Neck / High-Risk Skin Cancer

               -  Lung Cancer

               -  Breast Cancer

               -  Prostate Cancer

               -  Central Nervous System Tumors

               -  Gastrointestinal System Cancer

               -  Gynecologic cancer

               -  Other disease sites permitted at PI discretion

        Exclusion Criteria:

          -  Previous positive test for SARS-CoV-2

          -  Previous positive serology test for SARS-CoV-2

          -  Recent Chest CT meeting CT exclusion criteria

          -  Live in a skilled nursing facility with COVID-19 symptoms (Temp >38 C in addition to
             sore throat, cough, wheezing, chest tightness, shortness of breath, body aches or
             chills, diarrhea, anosmia)

          -  Known hypersensitivity to hydroxychloroquine or 4-aminoquinoline derivatives

          -  Pre-existing retinopathy

          -  Known chronic kidney disease, stage 4 or 5, or receiving dialysis

          -  Breast Feeding

          -  Tamoxifen

          -  Absolute neutrophil Count <1,000/ml at registration

          -  Concurrent use of any other quinine derivative

          -  Antiarrhythmic medications: amiodarone, sotalol, dofetilide, procainamide, quinidine,
             flecainide

          -  Glucose-6-phosphate dehydrogenase deficiency

          -  Pre-treatment corrected QT interval (QTc) ≥470 milliseconds**

          -  Prisoners

          -  Inability to participate

          -  Psoriasis

          -  History of suicidal ideation

          -  CT Criteria for Enrollment Exclusion (Optional - only for patients who received a
             diagnostic CT as part of standard of care or a thoracic CT as part of radiation
             simulation): All patients with COVID-19 typical radiographic findings on CT Chest as
             defined by the RSNA will be excluded. Patients with any NEW COVID-19 indeterminate
             radiographic findings on CT Chest that are concerning for COVID-19 will be excluded.
             COVID-19 indeterminate features are permitted if they can be demonstrated as STABLE on
             prior (>14 calendar days) CT Chest or PET/CT. If no prior comparison is available AND
             any intermediate or typical feature is present, the patient is not eligible.

          -  COVID-19 Atypical Features

               -  Isolated lobar or segmental consolidation without GGO

               -  Discrete small nodules (centrilobular, "tree-in-bud")

               -  Lung cavitation

               -  Smooth interlobular septal thickening with pleural effusion

          -  COVID-19 Indeterminate Features

               -  Multifocal, diffuse, perihilar, or unilateral GGO with or without consolidation
                  lacking a specific distribution and are non-rounded or non-peripheral

               -  Few very small GGO with a non-rounded and non-peripheral distribution

          -  COVID-19 Typical Features

               -  Peripheral, bilateral GGO with or without consolidation or visible intralobular
                  lines ("crazy paving")

               -  Multifocal GGO of rounded morphology with or without consolidation or visible
                  intralobular lines ("crazy paving")

               -  Reverse Halo sign or other findings of organizing pneumonia ** If pre-treatment
                  QTC can be decreased to <470, the patient can be re-considered for trial.
No condition on gender to be admitted to the trial.
No healthy subjects accepted to join the trial.
Subject must be at least 18 Years old.


Eligibility (NLI label): Contradiction