1. unable to provide consent; diagnosis of dementia or other significant neurocognitive disorder; 2. current hospitalization; 3. patient requiring long term oxygen treatment of \> 5 l o2/min because of a chronic lung condition at time of recruitment; 4. known intolerance/allergy to sulfone; 5. pregnant or breastfeeding women or is considering becoming pregnant during the study and for 3 months after the last dose of study medication; 6. concurrent malignancy on systemic chemotherapy or immunotherapy; 7. significantly impaired renal function within the past year reported by history and estimated glomerular filtration rate (egfr) \< 60 ml/min at screening 8. severely underweight (≤ 40 kg) 9. g6pd deficiency (previous jaundice, jaundice with foods such as beans, or medication such as sulfa drugs, nsaids, quinolones, hydroxychloroquine or vitamin c), significant blood dyscrasia or anemia (hb \<12.0 g/dl in women and \<13.0 g/dl in men; platelet count \<50 x 10\^9/l or \< lower limit of normal at screening) 10. impairment liver function \[\> 2 times the upper limit of normal (uln) at screening at screening for ast, alt, alp, ggt, albumin or bilirubin), liver cirrhosis or hepatitis 11. current use of folic acid antagonists (such as pyrimethamine), nitrofurantoin or primaquine 12. currently taking oral dapsone for dermatological or other indications 13. currently taking hydroxychloroquine or if have taken it within the last 6 months 14. currently on any of the following medications: aminolevulinic acid; cladribine; clozapine; deferiprone; prilocaine; saquinavir; sodium nitrite, rifampin or st. john's wort 15. received any of the following vaccines in the last 1 year : cholera vaccine live; typhoid vaccine, live; bcg (bacillus calmette and guérin) 16. currently taking any the following anticonvulsants : carbamazepine, phenytoin, levetiracetam and gabapentin 17. currently participating in other interventional trials 18. inability to provide contact details of caregiver/ next of kin to be contacted for study follow-up as participant's surrogate 19. currently taking trimethoprim

1. unable to provide consent; diagnosis of dementia or other significant neurocognitive disorder; 2. current hospitalization; 3. patient requiring long term oxygen treatment of \> 5 l o2/min because of a chronic lung condition at time of recruitment; 4. known intolerance/allergy to sulfone; 5. pregnant or breastfeeding women or is considering becoming pregnant during the study and for 3 months after the last dose of study medication; 6. concurrent malignancy on systemic chemotherapy or immunotherapy; 7. significantly impaired renal function within the past year reported by history and estimated glomerular filtration rate (egfr) \< 60 ml/min at screening 8. severely underweight (≤ 40 kg) 9. g6pd deficiency (previous jaundice, jaundice with foods such as beans, or medication such as sulfa drugs, nsaids, quinolones, hydroxychloroquine or vitamin c), significant blood dyscrasia or anemia (hb \<12.0 g/dl in women and \<13.0 g/dl in men; platelet count \<50 x 10\^9/l or \< lower limit of normal at screening) 10. impairment liver function \[\> 2 times the upper limit of normal (uln) at screening at screening for ast, alt, alp, ggt, albumin or bilirubin), liver cirrhosis or hepatitis 11. current use of folic acid antagonists (such as pyrimethamine), nitrofurantoin or primaquine 12. currently taking oral dapsone for dermatological or other indications 13. currently taking hydroxychloroquine or if have taken it within the last 6 months 14. currently on any of the following medications: aminolevulinic acid; cladribine; clozapine; deferiprone; prilocaine; saquinavir; sodium nitrite, rifampin or st. john's wort 15. received any of the following vaccines in the last 1 year : cholera vaccine live; typhoid vaccine, live; bcg (bacillus calmette and guérin) 16. currently taking any the following anticonvulsants : carbamazepine, phenytoin, levetiracetam and gabapentin 17. currently participating in other interventional trials 18. inability to provide contact details of caregiver/ next of kin to be contacted for study follow-up as participant's surrogate 19. currently taking trimethoprim

unable to provide consent; diagnosis of dementia or other significant neurocognitive disorder; current hospitalization; patient requiring long term oxygen treatment of > 5 l o2/min because of a chronic lung condition at time of recruitment; known intolerance/allergy to sulfone; pregnant or breastfeeding women or is considering becoming pregnant during the study and for 3 months after the last dose of study medication; concurrent malignancy on systemic chemotherapy or immunotherapy; significantly impaired renal function within the past year reported by history and estimated glomerular filtration rate (egfr) < 60 ml/min at screening severely underweight (≤ 40 kg) g6pd deficiency (previous jaundice, jaundice with foods such as beans, or medication such as sulfa drugs, nsaids, quinolones, hydroxychloroquine or vitamin c), significant blood dyscrasia or anemia (hb <12.0 g/dl in women and <13.0 g/dl in men; platelet count <50 x 10^9/l or < lower limit of normal at screening) impairment liver function [> 2 times the upper limit of normal (uln) at screening at screening for ast, alt, alp, ggt, albumin or bilirubin), liver cirrhosis or hepatitis current use of folic acid antagonists (such as pyrimethamine), nitrofurantoin or primaquine currently taking oral dapsone for dermatological or other indications currently taking hydroxychloroquine or if have taken it within the last 6 months currently on any of the following medications: aminolevulinic acid; cladribine; clozapine; deferiprone; prilocaine; saquinavir; sodium nitrite, rifampin or st. john's wort received any of the following vaccines in the last 1 year : cholera vaccine live; typhoid vaccine, live; bcg (bacillus calmette and guérin) currently taking any the following anticonvulsants : carbamazepine, phenytoin, levetiracetam and gabapentin currently participating in other interventional trials inability to provide contact details of caregiver/ next of kin to be contacted for study follow-up as participant's surrogate currently taking trimethoprim

unable to provide consent; diagnosis of dementia or other significant neurocognitive disorder; current hospitalization; patient requiring long term oxygen treatment of > 5 l o2/min because of a chronic lung condition at time of recruitment; known intolerance/allergy to sulfone; pregnant or breastfeeding women or is considering becoming pregnant during the study and for 3 months after the last dose of study medication; concurrent malignancy on systemic chemotherapy or immunotherapy; significantly impaired renal function within the past year reported by history and estimated glomerular filtration rate (egfr) < 60 ml/min at screening severely underweight (≤ 40 kg) g6pd deficiency (previous jaundice, jaundice with foods such as beans, or medication such as sulfa drugs, nsaids, quinolones, hydroxychloroquine or vitamin c), significant blood dyscrasia or anemia (hb <12.0 g/dl in women and <13.0 g/dl in men; platelet count <50 x 10^9/l or < lower limit of normal at screening) impairment liver function [> 2 times the upper limit of normal (uln) at screening at screening for ast, alt, alp, ggt, albumin or bilirubin), liver cirrhosis or hepatitis current use of folic acid antagonists (such as pyrimethamine), nitrofurantoin or primaquine currently taking oral dapsone for dermatological or other indications currently taking hydroxychloroquine or if have taken it within the last 6 months currently on any of the following medications: aminolevulinic acid; cladribine; clozapine; deferiprone; prilocaine; saquinavir; sodium nitrite, rifampin or st. john's wort received any of the following vaccines in the last 1 year : cholera vaccine live; typhoid vaccine, live; bcg (bacillus calmette and guérin) currently taking any the following anticonvulsants : carbamazepine, phenytoin, levetiracetam and gabapentin currently participating in other interventional trials inability to provide contact details of caregiver/ next of kin to be contacted for study follow-up as participant's surrogate currently taking trimethoprim

1. unable to provide consent; diagnosis of dementia or other significant neurocognitive disorder; 2. current hospitalization; 3. patient requiring long term oxygen treatment of > 5 l o2/min because of a chronic lung condition at time of recruitment; 4. known intolerance/allergy to sulfone; 5. pregnant or breastfeeding women or is considering becoming pregnant during the study and for 3 months after the last dose of study medication; 6. concurrent malignancy on systemic chemotherapy or immunotherapy; 7. significantly impaired renal function within the past year reported by history and estimated glomerular filtration rate (egfr) < 60 ml/min at screening 8. severely underweight (≤ 40 kg) 9. g6pd deficiency (previous jaundice, jaundice with foods such as beans, or medication such as sulfa drugs, nsaids, quinolones, hydroxychloroquine or vitamin c), significant blood dyscrasia or anemia (hb <12.0 g/dl in women and <13.0 g/dl in men; platelet count <50 x 10^9/l or < lower limit of normal at screening) 10. impairment liver function [> 2 times the upper limit of normal (uln) at screening at screening for ast, alt, alp, ggt, albumin or bilirubin), liver cirrhosis or hepatitis 11. current use of folic acid antagonists (such as pyrimethamine), nitrofurantoin or primaquine 12. currently taking oral dapsone for dermatological or other indications 13. currently taking hydroxychloroquine or if have taken it within the last 6 months 14. currently on any of the following medications: aminolevulinic acid; cladribine; clozapine; deferiprone; prilocaine; saquinavir; sodium nitrite, rifampin or st. john's wort 15. received any of the following vaccines in the last 1 year : cholera vaccine live; typhoid vaccine, live; bcg (bacillus calmette and guérin) 16. currently taking any the following anticonvulsants : carbamazepine, phenytoin, levetiracetam and gabapentin 17. currently participating in other interventional trials 18. inability to provide contact details of caregiver/ next of kin to be contacted for study follow-up as participant's surrogate 19. currently taking trimethoprim

1. unable to provide consent; diagnosis of dementia or other significant neurocognitive disorder; 2. current hospitalization; 3. patient requiring long term oxygen treatment of > 5 l o2/min because of a chronic lung condition at time of recruitment; 4. known intolerance/allergy to sulfone; 5. pregnant or breastfeeding women or is considering becoming pregnant during the study and for 3 months after the last dose of study medication; 6. concurrent malignancy on systemic chemotherapy or immunotherapy; 7. significantly impaired renal function within the past year reported by history and estimated glomerular filtration rate (egfr) < 60 ml/min at screening 8. severely underweight (≤ 40 kg) 9. g6pd deficiency (previous jaundice, jaundice with foods such as beans, or medication such as sulfa drugs, nsaids, quinolones, hydroxychloroquine or vitamin c), significant blood dyscrasia or anemia (hb <12.0 g/dl in women and <13.0 g/dl in men; platelet count <50 x 10^9/l or < lower limit of normal at screening) 10. impairment liver function [> 2 times the upper limit of normal (uln) at screening at screening for ast, alt, alp, ggt, albumin or bilirubin), liver cirrhosis or hepatitis 11. current use of folic acid antagonists (such as pyrimethamine), nitrofurantoin or primaquine 12. currently taking oral dapsone for dermatological or other indications 13. currently taking hydroxychloroquine or if have taken it within the last 6 months 14. currently on any of the following medications: aminolevulinic acid; cladribine; clozapine; deferiprone; prilocaine; saquinavir; sodium nitrite, rifampin or st. john's wort 15. received any of the following vaccines in the last 1 year : cholera vaccine live; typhoid vaccine, live; bcg (bacillus calmette and guérin) 16. currently taking any the following anticonvulsants : carbamazepine, phenytoin, levetiracetam and gabapentin 17. currently participating in other interventional trials 18. inability to provide contact details of caregiver/ next of kin to be contacted for study follow-up as participant's surrogate 19. currently taking trimethoprim