1. on home/therapy oxygen (i.e. for chronic obstructive pulmonary disease (copd) patients) at baseline prior to development of covid-19 2. already using gammacore® (nvns) for other medical conditions 3. a history of aneurysm, intracranial hemorrhage, brain tumors, or significant head trauma 4. known or suspected severe atherosclerotic cardiovascular disease, severe carotid artery disease (e.g., bruits or history of transient ischemic attack or cerebrovascular accident), congestive heart failure, known severe coronary artery disease, myocardial infarction documented within past 90 days, or current or recent history of life-threatening arrhythmia (sustained ventricular tachycardia, ventricular fibrillation, second or third-degree heart block, uncontrolled atrial fibrillation or uncontrolled atrial flutter) 5. patients with clinically significant hypertension, hypotension, bradycardia, or tachycardia (as per investigator discretion) 6. current implantation of an electrical and/or neurostimulator device, including but not limited to a cardiac pacemaker or defibrillator, vagal neurostimulator, deep brain stimulator, spinal stimulator, bone growth stimulator, or cochlear implant 7. current implantation of metal cervical spine hardware or a metallic implant near the gammacore® stimulation site 8. belongs to a vulnerable population or has any condition such that his or her ability to provide informed consent, comply with the follow-up requirements, or provide self-assessments is compromised (e.g. homeless, developmentally disabled and prisoner) 9. compromised access to peripheral veins for blood sampling. 10. pregnant women 11. patients with active cancer or those who have had recent cancer treatment

1. on home/therapy oxygen (i.e. for chronic obstructive pulmonary disease (copd) patients) at baseline prior to development of covid-19 2. already using gammacore® (nvns) for other medical conditions 3. a history of aneurysm, intracranial hemorrhage, brain tumors, or significant head trauma 4. known or suspected severe atherosclerotic cardiovascular disease, severe carotid artery disease (e.g., bruits or history of transient ischemic attack or cerebrovascular accident), congestive heart failure, known severe coronary artery disease, myocardial infarction documented within past 90 days, or current or recent history of life-threatening arrhythmia (sustained ventricular tachycardia, ventricular fibrillation, second or third-degree heart block, uncontrolled atrial fibrillation or uncontrolled atrial flutter) 5. patients with clinically significant hypertension, hypotension, bradycardia, or tachycardia (as per investigator discretion) 6. current implantation of an electrical and/or neurostimulator device, including but not limited to a cardiac pacemaker or defibrillator, vagal neurostimulator, deep brain stimulator, spinal stimulator, bone growth stimulator, or cochlear implant 7. current implantation of metal cervical spine hardware or a metallic implant near the gammacore® stimulation site 8. belongs to a vulnerable population or has any condition such that his or her ability to provide informed consent, comply with the follow-up requirements, or provide self-assessments is compromised (e.g. homeless, developmentally disabled and prisoner) 9. compromised access to peripheral veins for blood sampling. 10. pregnant women 11. patients with active cancer or those who have had recent cancer treatment

on home/therapy oxygen (i.e. for chronic obstructive pulmonary disease (copd) patients) at baseline prior to development of covid-19 already using gammacore® (nvns) for other medical conditions a history of aneurysm, intracranial hemorrhage, brain tumors, or significant head trauma known or suspected severe atherosclerotic cardiovascular disease, severe carotid artery disease (e.g., bruits or history of transient ischemic attack or cerebrovascular accident), congestive heart failure, known severe coronary artery disease, myocardial infarction documented within past 90 days, or current or recent history of life-threatening arrhythmia (sustained ventricular tachycardia, ventricular fibrillation, second or third-degree heart block, uncontrolled atrial fibrillation or uncontrolled atrial flutter) patients with clinically significant hypertension, hypotension, bradycardia, or tachycardia (as per investigator discretion) current implantation of an electrical and/or neurostimulator device, including but not limited to a cardiac pacemaker or defibrillator, vagal neurostimulator, deep brain stimulator, spinal stimulator, bone growth stimulator, or cochlear implant current implantation of metal cervical spine hardware or a metallic implant near the gammacore® stimulation site belongs to a vulnerable population or has any condition such that his or her ability to provide informed consent, comply with the follow-up requirements, or provide self-assessments is compromised (e.g. homeless, developmentally disabled and prisoner) compromised access to peripheral veins for blood sampling. pregnant women patients with active cancer or those who have had recent cancer treatment

on home/therapy oxygen (i.e. for chronic obstructive pulmonary disease (copd) patients) at baseline prior to development of covid-19 already using gammacore® (nvns) for other medical conditions a history of aneurysm, intracranial hemorrhage, brain tumors, or significant head trauma known or suspected severe atherosclerotic cardiovascular disease, severe carotid artery disease (e.g., bruits or history of transient ischemic attack or cerebrovascular accident), congestive heart failure, known severe coronary artery disease, myocardial infarction documented within past 90 days, or current or recent history of life-threatening arrhythmia (sustained ventricular tachycardia, ventricular fibrillation, second or third-degree heart block, uncontrolled atrial fibrillation or uncontrolled atrial flutter) patients with clinically significant hypertension, hypotension, bradycardia, or tachycardia (as per investigator discretion) current implantation of an electrical and/or neurostimulator device, including but not limited to a cardiac pacemaker or defibrillator, vagal neurostimulator, deep brain stimulator, spinal stimulator, bone growth stimulator, or cochlear implant current implantation of metal cervical spine hardware or a metallic implant near the gammacore® stimulation site belongs to a vulnerable population or has any condition such that his or her ability to provide informed consent, comply with the follow-up requirements, or provide self-assessments is compromised (e.g. homeless, developmentally disabled and prisoner) compromised access to peripheral veins for blood sampling. pregnant women patients with active cancer or those who have had recent cancer treatment

1. on home/therapy oxygen (i.e. for chronic obstructive pulmonary disease (copd) patients) at baseline prior to development of covid-19 2. already using gammacore® (nvns) for other medical conditions 3. a history of aneurysm, intracranial hemorrhage, brain tumors, or significant head trauma 4. known or suspected severe atherosclerotic cardiovascular disease, severe carotid artery disease (e.g., bruits or history of transient ischemic attack or cerebrovascular accident), congestive heart failure, known severe coronary artery disease, myocardial infarction documented within past 90 days, or current or recent history of life-threatening arrhythmia (sustained ventricular tachycardia, ventricular fibrillation, second or third-degree heart block, uncontrolled atrial fibrillation or uncontrolled atrial flutter) 5. patients with clinically significant hypertension, hypotension, bradycardia, or tachycardia (as per investigator discretion) 6. current implantation of an electrical and/or neurostimulator device, including but not limited to a cardiac pacemaker or defibrillator, vagal neurostimulator, deep brain stimulator, spinal stimulator, bone growth stimulator, or cochlear implant 7. current implantation of metal cervical spine hardware or a metallic implant near the gammacore® stimulation site 8. belongs to a vulnerable population or has any condition such that his or her ability to provide informed consent, comply with the follow-up requirements, or provide self-assessments is compromised (e.g. homeless, developmentally disabled and prisoner) 9. compromised access to peripheral veins for blood sampling. 10. pregnant women 11. patients with active cancer or those who have had recent cancer treatment

1. on home/therapy oxygen (i.e. for chronic obstructive pulmonary disease (copd) patients) at baseline prior to development of covid-19 2. already using gammacore® (nvns) for other medical conditions 3. a history of aneurysm, intracranial hemorrhage, brain tumors, or significant head trauma 4. known or suspected severe atherosclerotic cardiovascular disease, severe carotid artery disease (e.g., bruits or history of transient ischemic attack or cerebrovascular accident), congestive heart failure, known severe coronary artery disease, myocardial infarction documented within past 90 days, or current or recent history of life-threatening arrhythmia (sustained ventricular tachycardia, ventricular fibrillation, second or third-degree heart block, uncontrolled atrial fibrillation or uncontrolled atrial flutter) 5. patients with clinically significant hypertension, hypotension, bradycardia, or tachycardia (as per investigator discretion) 6. current implantation of an electrical and/or neurostimulator device, including but not limited to a cardiac pacemaker or defibrillator, vagal neurostimulator, deep brain stimulator, spinal stimulator, bone growth stimulator, or cochlear implant 7. current implantation of metal cervical spine hardware or a metallic implant near the gammacore® stimulation site 8. belongs to a vulnerable population or has any condition such that his or her ability to provide informed consent, comply with the follow-up requirements, or provide self-assessments is compromised (e.g. homeless, developmentally disabled and prisoner) 9. compromised access to peripheral veins for blood sampling. 10. pregnant women 11. patients with active cancer or those who have had recent cancer treatment