- prior verified sars-cov-2 infection. - hypersensitivity reaction to chloroquine, hydroxychloroquine or 4-aminoquinolines - electrocardiogram with qtc (bazett's formula) > 450 ms in males and 460 ms in females - patients reliant on digoxin or amiodarone treatment - pre-existing psoriasis - any pre-existing maculopathy with vision reduction - prior sensorineural hearing loss - pre-existing severe liver insufficiency (spontaneous international normalized ratio >1.5 within the last year) - pre-existing epileptic disease requiring anti-epileptic medication - pregnancy or lactation - insurmountable language barrier - participation in other ongoing intervention trials investigating covid19-related outcomes

- prior verified sars-cov-2 infection. - hypersensitivity reaction to chloroquine, hydroxychloroquine or 4-aminoquinolines - electrocardiogram with qtc (bazett's formula) > 450 ms in males and 460 ms in females - patients reliant on digoxin or amiodarone treatment - pre-existing psoriasis - any pre-existing maculopathy with vision reduction - prior sensorineural hearing loss - pre-existing severe liver insufficiency (spontaneous international normalized ratio >1.5 within the last year) - pre-existing epileptic disease requiring anti-epileptic medication - pregnancy or lactation - insurmountable language barrier - participation in other ongoing intervention trials investigating covid19-related outcomes