None

None

1. positive urine pregnancy test at screening or females who intend to become pregnant during the study. 2. covid-19 signs associated with severe respiratory distress or imminent serious medical outcomes.^^ ^^potential study subjects presenting with any of the following should be referred for immediate medical care and are not eligible for the study - fever > 104° f - cough with sputum production - rales and/or rhonchi - difficulty breathing with respiratory distress defined by a respiratory rate ≥30 per minute, heart rate ≥125 per minute, spo2 ≤93% on room air at sea level or pao2/fio2 <300. - persistent pain or pressure in the chest - confusion 3. any medical disease or condition that, in the opinion of the site principal investigator (pi) or appropriate sub-investigator, precludes study participation. 4. self-reported vaccination with at least one dose of covid-19 vaccine or history of covid-19 within the past 6 months. 5. reports a recent positive test result (within the past 6 months) for hepatitis a, hepatitis b or, hepatitis c virus antibody, or hiv-1 antibodies at screening. 6. has a history of alcohol abuse or other recreational drug (excluding cannabis) use within 1 month of study day 1. 7. currently enrolled in or plans to participate in another clinical trial with a therapeutic investigational agent (e.g., monoclonal antibody, oral protease inhibitor) that will be received during the study period. 8. history of systemic antiviral therapies (e.g., remdesivir) within the past 30 days. 9. history of oral or parenteral corticosteroid use within the past 30 days. active use of nasal or inhalable steroids is also exclusionary. topical steroids are not exclusionary. 10. has a history of hypersensitivity or severe allergic reaction (e.g., anaphylaxis, generalized urticaria, angioedema, other significant reaction) to sun exposure. 11. currently undergoing photodynamic therapy (pdt) or photochemotherapy (puva) for an unrelated disease or condition that utilizes photosensitizing drugs including but not limited to 5-aminolevulinic acid, methyl-5-aminolevulinic acid, porfimer sodium, methoxsalen (8-methoxypsoralen), 5-methoxypsoralen, trioxsalen. 12. has any oral abnormality (e.g., ulcer, oral candidiasis, oral mucositis, gingivitis) that in the opinion of the investigator would interfere with device use and evaluation. 13. any intra-oral body piercings that cannot be removed and remain removed for the duration of the study. metal orthodontia is permitted as braces will be covered by the device mouthpiece. 14. any individual without teeth or with a dental malformation that precludes directed use of the device as intended.

1. positive urine pregnancy test at screening or females who intend to become pregnant during the study. 2. covid-19 signs associated with severe respiratory distress or imminent serious medical outcomes.^^ ^^potential study subjects presenting with any of the following should be referred for immediate medical care and are not eligible for the study - fever > 104° f - cough with sputum production - rales and/or rhonchi - difficulty breathing with respiratory distress defined by a respiratory rate ≥30 per minute, heart rate ≥125 per minute, spo2 ≤93% on room air at sea level or pao2/fio2 <300. - persistent pain or pressure in the chest - confusion 3. any medical disease or condition that, in the opinion of the site principal investigator (pi) or appropriate sub-investigator, precludes study participation. 4. self-reported vaccination with at least one dose of covid-19 vaccine or history of covid-19 within the past 6 months. 5. reports a recent positive test result (within the past 6 months) for hepatitis a, hepatitis b or, hepatitis c virus antibody, or hiv-1 antibodies at screening. 6. has a history of alcohol abuse or other recreational drug (excluding cannabis) use within 1 month of study day 1. 7. currently enrolled in or plans to participate in another clinical trial with a therapeutic investigational agent (e.g., monoclonal antibody, oral protease inhibitor) that will be received during the study period. 8. history of systemic antiviral therapies (e.g., remdesivir) within the past 30 days. 9. history of oral or parenteral corticosteroid use within the past 30 days. active use of nasal or inhalable steroids is also exclusionary. topical steroids are not exclusionary. 10. has a history of hypersensitivity or severe allergic reaction (e.g., anaphylaxis, generalized urticaria, angioedema, other significant reaction) to sun exposure. 11. currently undergoing photodynamic therapy (pdt) or photochemotherapy (puva) for an unrelated disease or condition that utilizes photosensitizing drugs including but not limited to 5-aminolevulinic acid, methyl-5-aminolevulinic acid, porfimer sodium, methoxsalen (8-methoxypsoralen), 5-methoxypsoralen, trioxsalen. 12. has any oral abnormality (e.g., ulcer, oral candidiasis, oral mucositis, gingivitis) that in the opinion of the investigator would interfere with device use and evaluation. 13. any intra-oral body piercings that cannot be removed and remain removed for the duration of the study. metal orthodontia is permitted as braces will be covered by the device mouthpiece. 14. any individual without teeth or with a dental malformation that precludes directed use of the device as intended.