inclusion criteria: * able to give informed consent * subjects meeting the following criteria by sub-study: sub-study 1: 50-75 years of age; self-reporting as having a fever within four days prior to time of enrollment; and not requiring hospitalization. enrolled individuals will undergo testing for covid-19 and sent home for self-quarantine.participant must be willing and able to provide informed consent, agree to testing for covid-19 at time of enrollment to confirm diagnosis and two weeks at the end of treatment. sub-study 2: currently employed as a health care worker. health care workers are defined as : * medical doctor (md) * doctor of osteopathic medicine (do) * nurse practitioner (np) * physician's assistant (pa) * registered nurse (rn) * other members of the medical care team with significant covid-19 exposure; health care workers meeting the following criteria: * asymptomatic and presumed negative for covid-19 (no confirmatory testing conducted); * scheduled for an average of \>20 hours per week of clinical care over the next 2 months. participant must agree to standard clinical guidelines and undergo covid-19 testing upon the presentation of symptoms indicative of an influenza like illness; if a confirmatory covid-19 diagnosis is given, participant will be offered to cross-over to hcq 600 mg qd. * willing to report compliance with hcq in the form of a diary and participate in other forms of self-reporting (e.g., symptom tracker and experience log). * subjects are willing and able to go to designated areas for testing of covid-19/sars-cov-2 (severe acute respiratory syndrome coronavirus 2). * participants must be able to swallow and retain oral medication and must not have any clinically significant gastrointestinal abnormalities that may alter absorption such as malabsorption syndrome or major resection of the stomach or bowels. * participants must have adequate baseline organ function

inclusion criteria: * able to give informed consent * subjects meeting the following criteria by sub-study: sub-study 1: 50-75 years of age; self-reporting as having a fever within four days prior to time of enrollment; and not requiring hospitalization. enrolled individuals will undergo testing for covid-19 and sent home for self-quarantine.participant must be willing and able to provide informed consent, agree to testing for covid-19 at time of enrollment to confirm diagnosis and two weeks at the end of treatment. sub-study 2: currently employed as a health care worker. health care workers are defined as : * medical doctor (md) * doctor of osteopathic medicine (do) * nurse practitioner (np) * physician's assistant (pa) * registered nurse (rn) * other members of the medical care team with significant covid-19 exposure; health care workers meeting the following criteria: * asymptomatic and presumed negative for covid-19 (no confirmatory testing conducted); * scheduled for an average of \>20 hours per week of clinical care over the next 2 months. participant must agree to standard clinical guidelines and undergo covid-19 testing upon the presentation of symptoms indicative of an influenza like illness; if a confirmatory covid-19 diagnosis is given, participant will be offered to cross-over to hcq 600 mg qd. * willing to report compliance with hcq in the form of a diary and participate in other forms of self-reporting (e.g., symptom tracker and experience log). * subjects are willing and able to go to designated areas for testing of covid-19/sars-cov-2 (severe acute respiratory syndrome coronavirus 2). * participants must be able to swallow and retain oral medication and must not have any clinically significant gastrointestinal abnormalities that may alter absorption such as malabsorption syndrome or major resection of the stomach or bowels. * participants must have adequate baseline organ function

inclusion criteria: - able to give informed consent - subjects meeting the following criteria by sub-study: sub-study 1: 50-75 years of age; self-reporting as having a fever within four days prior to time of enrollment; and not requiring hospitalization. enrolled individuals will undergo testing for covid-19 and sent home for self-quarantine.participant must be willing and able to provide informed consent, agree to testing for covid-19 at time of enrollment to confirm diagnosis and two weeks at the end of treatment. sub-study 2: currently employed as a health care worker. health care workers are defined as : - medical doctor (md) - doctor of osteopathic medicine (do) - nurse practitioner (np) - physician's assistant (pa) - registered nurse (rn) - other members of the medical care team with significant covid-19 exposure; health care workers meeting the following criteria: - asymptomatic and presumed negative for covid-19 (no confirmatory testing conducted); - scheduled for an average of >20 hours per week of clinical care over the next 2 months. participant must agree to standard clinical guidelines and undergo covid-19 testing upon the presentation of symptoms indicative of an influenza like illness; if a confirmatory covid-19 diagnosis is given, participant will be offered to cross-over to hcq 600 mg qd. - willing to report compliance with hcq in the form of a diary and participate in other forms of self-reporting (e.g., symptom tracker and experience log). - subjects are willing and able to go to designated areas for testing of covid-19/sars-cov-2 (severe acute respiratory syndrome coronavirus 2). - participants must be able to swallow and retain oral medication and must not have any clinically significant gastrointestinal abnormalities that may alter absorption such as malabsorption syndrome or major resection of the stomach or bowels. - participants must have adequate baseline organ function

inclusion criteria: - able to give informed consent - subjects meeting the following criteria by sub-study: sub-study 1: 50-75 years of age; self-reporting as having a fever within four days prior to time of enrollment; and not requiring hospitalization. enrolled individuals will undergo testing for covid-19 and sent home for self-quarantine.participant must be willing and able to provide informed consent, agree to testing for covid-19 at time of enrollment to confirm diagnosis and two weeks at the end of treatment. sub-study 2: currently employed as a health care worker. health care workers are defined as : - medical doctor (md) - doctor of osteopathic medicine (do) - nurse practitioner (np) - physician's assistant (pa) - registered nurse (rn) - other members of the medical care team with significant covid-19 exposure; health care workers meeting the following criteria: - asymptomatic and presumed negative for covid-19 (no confirmatory testing conducted); - scheduled for an average of >20 hours per week of clinical care over the next 2 months. participant must agree to standard clinical guidelines and undergo covid-19 testing upon the presentation of symptoms indicative of an influenza like illness; if a confirmatory covid-19 diagnosis is given, participant will be offered to cross-over to hcq 600 mg qd. - willing to report compliance with hcq in the form of a diary and participate in other forms of self-reporting (e.g., symptom tracker and experience log). - subjects are willing and able to go to designated areas for testing of covid-19/sars-cov-2 (severe acute respiratory syndrome coronavirus 2). - participants must be able to swallow and retain oral medication and must not have any clinically significant gastrointestinal abnormalities that may alter absorption such as malabsorption syndrome or major resection of the stomach or bowels. - participants must have adequate baseline organ function