• Clinical risk based on age ≥ 55 years or an adult (age ≥ 18 years) with an immunosuppressed condition.
• Positive test for SARS-CoV-2 within ≤5 days (if >1 test, the first positive is within ≤5 days). Tests may include an institutional-based nucleic acid amplification test (NAAT), or any protocol-approved rapid test.
• Within ≤5 days from symptom onset, if symptomatic from current SARS-CoV-2 infection.
• Agrees to not participate in another clinical trial for the treatment or management of SARS-CoV-2 infection through Day 7, or until hospitalized or significant disease progression if prior to Day 7 (defined by ordinal category 4 or 5).
• Participant provides written informed consent prior to study procedures, and understands and agrees to adhere to planned study procedures through Day 28. Ongoing immunosuppressive condition or immunosuppressive treatment, includes: 1. Steroids equivalent to prednisone > 10 mg/day for at least the last 28 days 2. Rheumatologic or autoimmune disorder treated with a biologic or non-biologic immunosuppressive therapy 3. Antirejection medicine after solid organ or stem cell transplantation 4. Cancer treatment with systemic chemotherapy, biologic and/or cell-based therapy in the last 12 months 5. Primary or acquired severe B- or T-lymphocyte immune dysfunction 6. HIV infection 7. Splenectomy or functional asplenia
• Asymptomatic and had prior symptoms from the current infection that have now resolved (for >24 hours).
• Asymptomatic and has received a vaccination for COVID-19 (≥1 dose).
• Undergoing evaluation for possible admission to hospital for medical management (this does not include evaluation of possible hospitalization for public health purposes).
• Evidence of pneumonia and/or hypoxia due to COVID-19 (NOTE: chest imaging is not required, but if available it should not show new infiltrates suggestive of pneumonia; hypoxia is defined by new oxygen supplementation or increase above pre-illness level).
• Prior receipt of immunoglobulin product or passive immune therapy for SARS-CoV-2 in the past 90 days (i.e., convalescent plasma, SARS-CoV-2 monoclonal antibodies, or any IVIG).
• Any of the following thrombotic or procoagulant conditions or disorders: 1. acute coronary syndrome, cerebrovascular syndrome, pulmonary embolism, or deep venous thrombosis within 28 days of randomization. 2. prothrombin gene mutation 20210, homozygous Factor V Leiden mutations, antiphospholipid syndrome, or a deficiency in antithrombin III, protein C, or protein S.
• History of hypersensitivity to blood, plasma or IVIG excipients.
• Known immunoglobulin A (IgA) deficiency or anti-IgA antibodies.
• In the opinion of the investigator, any condition for which participation would not be in the best interest of the participant or that could prevent or confound protocol assessments.

1. Written informed consent obtained from subject or subject's legal representative 2. Be willing and able to adhere to the study visit schedule and other protocol requirements 3. Greater than or equal to 18 years of age at Visit 1 4. Documentation of a CF diagnosis as evidenced by one or more clinical features consistent with the CF phenotype and one or more of the following criteria:
• Sweat chloride ≥ 60 milliequivalent (mEq)/liter by quantitative pilocarpine iontophoresis test (QPIT)
• Two well-characterized mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene
• Abnormal nasal potential difference (NPD) (change in NPD in response to a low chloride solution and isoproteronol of less than -5 mV) 5. Documentation of NTM culture positive defined as follows:
• Two positive NTM culture results from sputum (or BAL) at least 28 days apart (these are the two qualifying positive cultures)
• Both qualifying positive culture results include M. avium complex, M. abscessus complex, or both M. avium and M. abscessus
• Both qualifying positive culture results include the same species or subspecies
• No cultures negative for NTM since the first of the two qualifying positive culture results 6. Current NTM species or subspecies has never been treated or previous treatment was associated with clearance of NTM and completed > 2 years prior to Day 1 7. Forced expiratory volume in 1 second (FEV1) ≥ 25 % of predicted value at Screening 8. Able to expectorate sputum 9. Clinically stable with no significant changes in health status within 7 days prior to Day 1 10. Enrolled in the CFF Cystic Fibrosis Foundation Patient Registry (CFFPR) 11. Willing to discontinue chronic azithromycin use for the duration of the study 1. Any of the following abnormal lab values at screening:
• Hemoglobin <10g/dL
• Platelets <100,000/mm3
• White blood cells (WBC) < 4,500/mm3
• Aspartate transaminase (AST), alanine transaminase (ALT), gamma-glutamyl transferase (GGT), or alkaline phosphatase (ALP) ≥3 x upper limit of normal
• Serum creatinine > 2.0 mg/dl and ≥1.5 x upper limit of normal
• Ionized calcium ≤ lower limit of normal (only performed if total calcium is ≤ lower limit of normal) 2. History of solid organ or hematological transplantation 3. Use of bisphosphonates within 7 days prior to Day 1 4. Known sensitivity to gallium 5. Use of any investigational drug and/or participated in any interventional clinical trial within 28 days prior to Day 1 6. In the opinion of the Investigator, features of active NTM disease are present (e.g., clinical worsening is likely due to NTM disease despite definitive treatment of co-pathogens and/or acute exacerbations) 7. Undergoing treatment for NTM disease or anticipate beginning treatment within 3 months 8. Current diagnosis of osteoporosis 9. For people of childbearing potential:
• Positive pregnancy test at Visit 1 or
• Lactating or
• Unwilling to practice a medically acceptable form of contraception (acceptable forms of contraception: abstinence, hormonal birth control, intrauterine device, or barrier method plus a spermicidal agent), unless surgically sterilized or postmenopausal during the study 10. For people able to father a child: unwilling to use adequate contraception (as determined by the investigator) during the study 11. Has any other condition that, in the opinion of the Site Investigator/designee, would preclude informed consent or assent, make study participation unsafe, complicate interpretation of study outcome data, or otherwise interfere with achieving the study objectives 12. New initiation of chronic therapy (greater than 21 days) within 28 days prior to the Enrollment Visit

• Male or female >1 year of age.
• Has undergone allogeneic cell transplantation ≥21 days prior to randomization and demonstrated engraftment with an absolute neutrophil count >500/mm^3, AND has one of the following: 1. AdV viremia DNA ≥10,000 copies/mL at screening, OR 2. Two consecutive and rising AdV viremia DNA results of ≥1,000 copies/mL at screening, AND 1. has absolute lymphocyte count <180/mm3, OR 2. has received T cell depletion.
• Contraceptive use by men and women should be consistent with local regulations regarding the methods of contraception for those participating in clinical studies and refrain from donating sperm or eggs for at least 90 days after treatment completion.
• Willing and able to provide signed informed consent.
• Has an HLA type matching with at least 1 suitably matched and available posoleucel VST line for infusion.
• Grade >2 acute GVHD
• Ongoing therapy with high-dose systemic corticosteroids
• Grade 4 diarrhea
• Uncontrolled viral (other than AdV), bacterial, or fungal infection(s)
• Requirement for fraction of inspired oxygen >0.5 to maintain arterial oxygen saturation >90% (via pulse oximetry) or need for mechanical ventilation.
• Prior therapy with anti-thymocyte globulin, alemtuzumab (Campath®), or other immunosuppressive T cell monoclonal antibodies within 28 days prior to randomization.
• Prior donor lymphocyte infusion or CD34+ stem cell infusion within 21 days prior to randomization.
• Use of vasopressors within 7 days prior to randomization.
• Use of any investigational antiviral agent, including brincidofovir, within 7 days prior to randomization.
• Lactating female unwilling to discontinue nursing prior to randomization.
• Severe allergy to any component of posoleucel or history of severe prior reactions to blood product transfusions.
• Positive for SARS-CoV-2 virus at screening.

• ≥ 18 years of age
• Hospitalized for COVID-19
• Enrolled within 72 hours of hospital admittance or 72 hours of positive COVID test
• Expected to require hospitalization for > 72 hours
• Imminent death
• Requirement for chronic mechanical ventilation via tracheostomy prior to hospitalization
• Pregnancy Inclusion Criteria for Arm E Inclusion criteria contained in the master protocol in addition to the following: Moderate illness severity
•defined as non-ICU level of care at the time of randomization (not receiving high flow nasal oxygen (HFNO), non-invasive ventilation (NIV), invasive ventilation (IV), vasopressors or inotropes, or extracorporeal membrane oxygenation (ECMO) OR Severe illness severity
•defined as ICU level of care at the time of randomization (receiving HFNO, NIV, IV, vasopressors or inotropes, or ECMO) For moderate illness severity, participants are required to meet one or more of the following risk criteria: 1. Age ≥ 65 years or 2. ≥2 of the following -
• O2 supplementation > 2 liters per minute
• BMI ≥ 35
• GFR ≤ 60
• History of Type 2 diabetes
• History of heart failure (regardless of ejection fraction)
• D dimer ≥ 2x the site's upper limit of normal (ULN)
• Troponin ≥ 2x the site's ULN
• BNP≥100 pg/mL or NT-proBNP≥300 pg/mL
• CRP ≥50 mg/L Exclusion Criteria for Arm E
• Exclusion criteria contained in the master protocol, and
• Any condition that, in the opinion of the investigator, precludes the use of crizanlizumab such as uncontrolled bleeding or severe anemia (hemoglobin<4 g/dL)
• Open label treatment with crizanlizumab within the past three months Inclusion Criteria for Arm F Inclusion criteria contained in the master protocol in addition to the following: Moderate illness severity
•defined as non-ICU level of care at the time of randomization (not receiving high flow nasal oxygen (HFNO), non-invasive ventilation (NIV), invasive ventilation (IV), vasopressors or inotropes, or extracorporeal membrane oxygenation (ECMO)) OR Severe illness severity
•defined as ICU level of care at the time of randomization (receiving HFNO, NIV, IV, vasopressors or inotropes, or ECMO) For moderate illness severity, participants are required to meet one or more of the following risk criteria: 1. Age ≥ 65 years or 2. ≥2 of the following-
• O2 supplementation > 2 liters per minute
• BMI ≥ 35
• GFR ≤ 60
• History of Type 2 diabetes
• History of heart failure (regardless of ejection fraction)
• D dimer ≥ 2x the site's upper limit of normal (ULN)
• Troponin ≥ 2x the site's ULN
• BNP≥100 pg/mL or NT-proBNP≥300 pg/mL
• CRP ≥50 mg/L Exclusion Criteria for Arm F In addition to the exclusion criteria noted in the master protocol, arm-specific exclusion criteria are as follows:
• Known hypersensitivity to any SGLT2 inhibitors
• Type 1 diabetes
• History of diabetic ketoacidosis
• eGFR <20 and/or requirement for renal replacement therapy
• Open label treatment with any SGLT2 inhibitor
• Based on a recommendation from the ACTIV4 DSMB on December 19, 2020, enrollment of patients requiring ICU level of care into the therapeutic anti-coagulation arm was stopped due to meeting a futility threshold and a potential for harm for this sub-group could not be excluded. Enrollment continues for moderately ill hospitalized COVID-19 patients.
• Based on a recommendation from the ACTIV4 DSMB on June 18, 2021, enrollment of patients not requiring ICU level of care and randomized to P2Y12 or standard care was stopped due to meeting a futility threshold. Enrollment continues for severely ill (ICU level of care) hospitalized COVID-19 patients.

1. Subjects must exhibit symptoms (including at least one lower respiratory symptom such as shortness of breath or dyspnea) of COVID-19 disease at screening and/or since the start of their hospitalization (may include treated symptoms; 2. Subjects must be 18 years and older, of either gender; 3. Subjects must have at least one of the following factors/co-morbidities: 1. Controlled or uncontrolled diabetes; 2. Pre-existing cardiovascular disease, including hypertension; 3. Pre-existing respiratory disease such as COPD, asthma, emphysema; 4. Active or a former smoker with a 20 pack-years of smoking history; 5. Obesity as depicted by body mass index ≥ 30; 6. Laboratory tests indicative of a higher risk of COVID-19-related complications, such as troponin >1.5 upper limit of normal, D-dimer >3.0 upper limit of normal and/or CRP >1.5 upper limit of normal 7. Patient aged 70 years and older who, based on the judgment of the Investigator, is at a higher risk of developing complications. 4. Subjects must have a documented positive test for the SARS-CoV-2 virus; 5. Subjects must be under observation by, or admitted to a controlled facility or hospital to receive standard-of-care for COVID-19 disease (care for COVID-19 disease should be for no more than 72 hours before screening, including any prior stay in another hospital); 6. Subject's health status must be 3 or 4 on the ordinal scale, and not previously a "5 or a 6"; 7. If female, must be either post-menopausal (one year or greater without menses), surgically sterile, or, for female subjects of child-bearing potential who are capable of conception, must be: practicing a highly effective method of birth control (acceptable methods include intrauterine device, complete abstinence, spermicide + barrier, male partner surgical sterilization, or hormonal contraception) during the study and through 30 days after the last dose of the study medication. Periodical abstinence is not classified as an effective method of birth control. A pregnancy test must be negative at the Screening Visit; 8. Subjects must have the ability to understand and give informed consent, which can be verbal with a witness, according to local requirements; 9. Subjects deemed capable of adequate compliance including attending scheduled visits for the duration of the study; 10. Subjects must be able to swallow the study drug capsules. 1. Pregnancy or breastfeeding; 2. Health condition deemed to possibly interfere with the study endpoints and/or the safety of the patients. For example, the following conditions should be considered contraindicated for participation in the study, but this is not an exhaustive list. In case of doubt, the Investigator should consult with the sponsor's medical representative: 1. Presence of inherited retinitis pigmentosa; 2. Presence or history of liver failure (Child-Pugh B or C); 3. Presence or history of stage 4 severe chronic kidney disease or dialysis requirement; 4. Febrile neutropenia; 5. Presence of end-stage cancer. 3. Known history of a severe allergy or sensitivity to retinoids, or with known allergies to excipients in the oral capsule formulation proposed to be used in the study; 4. Participation in another drug clinical trial within 30 days (or a minimum of 5 elimination half-lives) prior to screening, except ongoing participation in non-interventional studies; 5. Calculated creatinine clearance (CrCL, using the Cockroft-Gault equation for example) <50 ml/min; 6. Presence of total bilirubin >1.5 x ULN (in the absence of demonstrated Gilbert's syndrome), ALT and/or AST > 2.5 x ULN; 7. Patient expected to be transferred to ICU or die in the next 24 hours.

• Participant meets the standard criteria for liver transplant at the local center.
• Participants being listed for a simultaneous liver kidney (SLK) are eligible if participants meet the standard criteria for both organs.
• Participant is able to understand and provide informed consent.
• Participant meets with an independent advocate per the HIV Organ Policy Equity (HOPE) Act Safeguards and Research Criteria.
• Documented HIV infection (by any licensed assay or documented history of detectable HIV-1 RNA).*
• Participant is ≥ 18 years old.
• Opportunistic complications: prior history of certain opportunistic infections is not an exclusion if the participant has received appropriate therapy and has no evidence of active disease. Medical record documentation should be provided whenever possible.
• CD4+ T-cell count: ≥ 100/µL within 16 weeks prior to transplant if no history of AIDS-defining infection; or ≥ 200 μL if history of opportunistic infection is present.
• HIV-1 RNA is below 50 RNA/mL.* Viral blips between 50-400 copies will be allowed as long as there are not consecutive measurements > 200 copies/mL. *Organ recipients who are unable to tolerate anti-retroviral therapy (ART) due to organ. failure or recently started ART may be eligible despite a detectable viral load if safe and effective ART to be used by the recipient after transplantation is described.
• Participant must have or be willing to start seeing a primary medical care provider with expertise in HIV management.
• Participant is willing to comply with all medications related to participant's transplant and HIV management.
• For participants with a history of aspergillus colonization or disease, no current clinical evidence of active disease.
• Agreement to use contraception.
• Participant is not suffering from significant wasting (e.g. body mass index < 21) thought to be related to HIV disease.
• Participant has a history of progressive multifocal leukoencephalopathy (PML), or primary central nervous system (CNS) lymphoma.*
• Participant is pregnant or breastfeeding. (Note: Participants who become pregnant post-transplant will continue to be followed in the study and will be managed per local site practice. Women that become pregnant should not breastfeed.)
• Past or current medical problems or findings from medical history, physical examination or laboratory testing that are not listed above, which, in the opinion of the investigator, may pose additional risks from participation in the study, may interfere with the participant's ability to comply with study requirements or that may impact the quality or interpretation of the data obtained from the study.

Key
• Aged < 18 years of age who meet one of the following weight criteria (where permitted according to local law and approved nationally and by relevant institutional review board (IRB) or independent ethics committee (IEC)).
• a) Cohort 1: ≥ 12 years to < 18 years of age and weight at screening ≥ 40 kg
• b) Cohorts 2-4: ≥ 28 days to < 18 years of age and weight at screening ≥ 3 kg and < 40 kg
• c) Cohort 5: ≥ 14 days to < 28 days of age, gestational age > 37 weeks and weight at screening ≥ 2.5 kg
• d) Cohort 6: 0 days to < 14 days of age, gestational age > 37 weeks and birth weight of ≥ 2.5 kg
• e) Cohort 7: 0 days to < 56 days of age, gestational age ≤ 37 weeks and birth weight of ≥ 1.5 kg
• f) Cohort 8: < 12 years of age and weight at screening ≥ 40 kg
• Severe acute respiratory syndrome coronavirus (SARS-CoV-2) infection confirmed by polymerase chain reaction (PCR)
• Hospitalized and requiring medical care for coronavirus disease 2019 (COVID-19) Key
• Concurrent treatment with other agents with actual or possible direct antiviral activity against SARS-CoV-2 < 24 hours prior to study drug dosing
• Alanine Aminotransferase (ALT) or aspartate aminotransferase (AST) > 5 X upper limit of normal (ULN)
• Estimated glomerular filtration rate (eGFR) < 30 mL/min/1.73m^2 using Schwartz formula for individuals ≥ 1 year of age
• Creatinine above protocol specified thresholds for < 1 year of age
• Positive pregnancy test at Screening only for female of child bearing potential. Note: If female participants who become pregnant during the study or are discovered to be pregnant after receiving at least one dose may continue study drug, after discussion with the investigator
• On renal replacement therapies (intermittent hemodialysis (iHD), peritoneal dialysis (PD), continuous renal replacement therapy (CRRT)) Note: Other protocol defined Inclusion/Exclusion criteria may apply

• Biopsy proven (from primary lesion and/or lymph nodes) diagnosis of cancer of the nasopharynx
• Sites are required to complete Step 1 registration before submitting specimens for EBV DNA analysis.
• Patients must have detectable pretreatment plasma EBV DNA, determined by the central lab prior to Step 2 registration (see Section 10.2 for details of specimen submission).
• For patients who have detectable plasma EBV DNA tested at one of the credentialed central labs (listed on the EBV DNA Testing Specimen Transmittal form) within 28 days prior to Step 1 registration: that test result can be used for eligibility without the need for re-testing. To use this test result for eligibility, the central lab must enter the test result through the pathology portal, and the site must follow the instructions in Section 5.4.
• Stage II-IVB disease (AJCC, 7th ed.) with no evidence of distant metastasis, based upon the following minimum diagnostic workup:
• History/physical examination by a Medical Oncologist or Clinical Oncologist or Radiation Oncologist or ENT, which must include an endoscopic evaluation, a complete list of current medications, and assessment of weight and weight loss in the past 6 months within 21 days prior to registration;
• Evaluation of tumor extent required within 28 days prior to registration:
• MRI of the nasopharynx and neck; or CT of the nasopharynx and neck with ≤ 3 mm contiguous slices with contrast and bone windows (to evaluate base of skull involvement). Note: If a treatment planning CT scan is used, it must be with ≤ 3 mm contiguous slices with contrast and be read by a radiologist. Please refer to section 6.3.2 for MRI requirement for target delineation.
• To rule out distant metastasis, patients must undergo the following imaging within 28 days prior to registration: 1. a CT scan with contrast of the chest and abdomen (required), and the pelvis (optional), or a total body PET/CT scan (non-contrast PET/CT is acceptable); 2. a bone scan only when there is suspicion of bone metastases (a PET/CT scan can substitute for the bone scan).
• Zubrod performance status 0-1 within 21 days prior to registration
• Absolute neutrophil count (ANC) ≥ 1,500 cells/mm^3
• Platelets ≥ 100,000 cells/mm^3
• Hemoglobin ≥ 8.0 g/dl (Note: the use of transfusion or other intervention to achieve hemoglobin [Hgb] ≥ 8.0 g/dl is acceptable)
• Total bilirubin ≤ 1.5 x institutional upper limit of normal (ULN)
• Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) ≤ 1.5 x institutional ULN
• Alkaline phosphatase ≤ 1.5 x institutional ULN
• Serum creatinine ≤ 1.5 mg/dl or calculated creatinine clearance (CC) ≥ 50 ml/min determined by 24-hour urine collection or estimated by Cockcroft-Gault formula
• Negative serum pregnancy test within 14 days prior to registration for women of childbearing potential
• Women of childbearing potential and male participants who are sexually active must agree to use a medically effective means of birth control throughout protocol treatment
• Patient must provide study specific informed consent prior to study entry, including the mandatory pre-treatment plasma EBV DNA assay
• Prior invasive malignancy (except node negative, non-melanomatous skin cancer) unless disease free for a minimum of 1095 days (3 years) (for example, carcinoma in situ of the breast, oral cavity, or cervix are all permissible)
• Prior systemic chemotherapy for the study cancer; note that prior chemotherapy for a different cancer is allowable; however, at least 6-weeks recovery is necessary if the last regimen included nitrosourea or mitomycin
• Prior radiotherapy to the region of the study cancer that would result in overlap of radiation therapy fields
• Patients with hearing loss assessed to be primarily sensorineural in nature, requiring a hearing aid, or intervention (i.e. interfering in a clinically significant way with activities of daily living); a conductive hearing loss that is tumor-related is allowed
• ≥ Grade 2 peripheral sensory neuropathy (CTCAE, v. 4.0)
• Severe, active co-morbidity, defined as follows:
• Major medical or psychiatric illness, which in the investigator's opinion would interfere with the completion of therapy and follow up or with full understanding of the risks and potential complications of the therapy
• Unstable angina and/or uncontrolled congestive heart failure within the past 6 months
• Myocardial infarction within the last 6 months
• Acute bacterial or fungal infection requiring intravenous antibiotics at the time of registration; note that patients switched from IV antibiotics and currently on oral antibiotics whose infection is assessed to be adequately treated or controlled are eligible
• Chronic Obstructive Pulmonary Disease exacerbation or other respiratory illness requiring hospitalization or precluding study therapy within 30 days prior to registration
• Acquired Immune Deficiency Syndrome (AIDS) based upon current Centers for Disease Control and Prevention (CDC) definition; note, however, that Human Immunodeficiency Virus (HIV) testing is not required for entry into this protocol. The need to exclude patients with AIDS from this protocol is necessary because the treatments involved in this protocol may be significantly immunosuppressive.
• Pregnancy or women of childbearing potential and men who are sexually active and not willing/able to use medically acceptable forms of contraception
• Prior allergic reaction to the study drug(s) involved in this protocol
• Patients with undetectable pre-treatment plasma EBV DNA

1. Diagnosis of COVID-19 by positive RT-PCR requiring hospitalization within 72 hours 2. Age ≥18 years old 3. Able to provide informed consent, or (as allowed by IRB), immediate availability of designated legally authorized representative to provide consent by proxy 4. Anticipated hospitalization for >48 hours 1. Participation in any other clinical trial with antiviral activity against COVID-19 2. Breastfeeding women 3. Known hypersensitivity to atovaquone or formulation excipient 4. Active treatment with rifampin 5. HIV patients with AIDS requiring treatment for Pneumocystis jirovecii or Toxoplasma gondii 6. Not expected to survive for 72 hours. 7) >14 days from symptom onset

• COVID-19 PCR positive (within 7 days)
• COVID-19 PCR pending
• COVID-19 high clinical suspicion
• Patient without Prior Research Authorization (applicable to Mayo Clinic sites)
• Non COVID-19 related admissions
• Repeated Admission to ICUs/Hospital

INCLUSION CRITERIA 1. Fluent in English or Spanish; 2. Age 18 and over; 3. Self-reported symptoms suggestive of acute SARSCOV2 infection; 4. Under investigation for SARSCOV2 (defined as a patient who has received any screening or diagnostic test used to detect the presence of COVID19 including any FDA approved or authorized molecular or antigen-based assay) within the last 42 days. EXCLUSION CRITERIA 1. Unable to provide informed consent; 2. Study team unable to confirm result of diagnostic test for SARSCOV2; 3. Does not have access to a hand-held device or computer that would allow for digital participation in the study; 4. Individuals who are prisoners while participating in the study.

1. Diagnosis of Multiple Sclerosis , ADEM, anti-MOG antibody associated CNS demyelination 2. Age 12 to 18 inclusive at time of enrollment 3. Ability of parent or legal guardian to provide informed consent if participant is under 18. 4. Ability of patients age 12 and older to give assent 5. Completion of the signed HIPPA authorization form by a parent or legal guardian or by participants (18 years of age). 1. Known history of traumatic brain injury that required medical care 2. Non-English speaking (based on standardized neuropsychological testing and questionnaires) 3. Claustrophobic, pregnant, the presence of metallic braces, implants or medical devices that are unsafe at 3T or 7T and/or interfere with the MRI/MRS signals

Inclusion 1. Male or female patients, age ≥18 years 2. Being managed for chronic hepatitis B (CHB), including patients who have achieved functional cure and patients with concurrent delta hepatitis Exclusion 1. Inability to provide written informed consent 2. Known history of Human Immunodeficiency Virus (HIV) 3. History of liver transplantation