1. pregnant or breastfeeding, or intending to become pregnant during the study or within 30 days after the final dose or who are not willing to use a highly effective method of contraception. 2. hiv-infected subjects with viral load greater than 400 copies/ml or cd4 count less than 200 cell/µl from known medical history within past 6 months of the screening visit. 3. subject with moderate to severe hepatic impairment or acute liver failure. 4. known severe kidney disease. 5. participated in other intervention studies within 6 months. 6. has any condition for which, in the opinion of the investigator, participation would not be in the best interest of the participant or that could prevent, limit, or confound the protocol-specified assessments including but not limited to participants who are not expected to survive longer than 48 hours after randomization, or participants who are expected to require mechanical ventilation within 48 hours after randomization, or participants with a recent history of mechanical ventilation. 7. subjects receiving any medications or substances that are strong inhibitors or inducers of cyp3a within 14 days of randomization. 8. received, ongoing or planed treatment with other anti-sars cov 2 therapeutics (including but not limited to known anti-sars cov 2 antibodies, small molecule antivirals, etc., other than remdesivir). 9. other conditions that may increase the risk of study participation or, in the investigator's judgment, make the participant inappropriate for the study. 10. have known hypersensitivity to fb2001 or its excipients. 11. any planned vaccine within 28 days following the last administration of fb2001 for injection.

1. pregnant or breastfeeding, or intending to become pregnant during the study or within 30 days after the final dose or who are not willing to use a highly effective method of contraception. 2. hiv-infected subjects with viral load greater than 400 copies/ml or cd4 count less than 200 cell/µl from known medical history within past 6 months of the screening visit. 3. subject with moderate to severe hepatic impairment or acute liver failure. 4. known severe kidney disease. 5. participated in other intervention studies within 6 months. 6. has any condition for which, in the opinion of the investigator, participation would not be in the best interest of the participant or that could prevent, limit, or confound the protocol-specified assessments including but not limited to participants who are not expected to survive longer than 48 hours after randomization, or participants who are expected to require mechanical ventilation within 48 hours after randomization, or participants with a recent history of mechanical ventilation. 7. subjects receiving any medications or substances that are strong inhibitors or inducers of cyp3a within 14 days of randomization. 8. received, ongoing or planed treatment with other anti-sars cov 2 therapeutics (including but not limited to known anti-sars cov 2 antibodies, small molecule antivirals, etc., other than remdesivir). 9. other conditions that may increase the risk of study participation or, in the investigator's judgment, make the participant inappropriate for the study. 10. have known hypersensitivity to fb2001 or its excipients. 11. any planned vaccine within 28 days following the last administration of fb2001 for injection.

pregnant or breastfeeding, or intending to become pregnant during the study or within 30 days after the final dose or who are not willing to use a highly effective method of contraception. hiv-infected subjects with viral load greater than 400 copies/ml or cd4 count less than 200 cell/µl from known medical history within past 6 months of the screening visit. subject with moderate to severe hepatic impairment or acute liver failure. known severe kidney disease. participated in other intervention studies within 6 months. has any condition for which, in the opinion of the investigator, participation would not be in the best interest of the participant or that could prevent, limit, or confound the protocol-specified assessments including but not limited to participants who are not expected to survive longer than 48 hours after randomization, or participants who are expected to require mechanical ventilation within 48 hours after randomization, or participants with a recent history of mechanical ventilation. subjects receiving any medications or substances that are strong inhibitors or inducers of cyp3a within 14 days of randomization. received, ongoing or planed treatment with other anti-sars cov 2 therapeutics (including but not limited to known anti-sars cov 2 antibodies, small molecule antivirals, etc., other than remdesivir). other conditions that may increase the risk of study participation or, in the investigator's judgment, make the participant inappropriate for the study. have known hypersensitivity to fb2001 or its excipients. any planned vaccine within 28 days following the last administration of fb2001 for injection.

pregnant or breastfeeding, or intending to become pregnant during the study or within 30 days after the final dose or who are not willing to use a highly effective method of contraception. hiv-infected subjects with viral load greater than 400 copies/ml or cd4 count less than 200 cell/µl from known medical history within past 6 months of the screening visit. subject with moderate to severe hepatic impairment or acute liver failure. known severe kidney disease. participated in other intervention studies within 6 months. has any condition for which, in the opinion of the investigator, participation would not be in the best interest of the participant or that could prevent, limit, or confound the protocol-specified assessments including but not limited to participants who are not expected to survive longer than 48 hours after randomization, or participants who are expected to require mechanical ventilation within 48 hours after randomization, or participants with a recent history of mechanical ventilation. subjects receiving any medications or substances that are strong inhibitors or inducers of cyp3a within 14 days of randomization. received, ongoing or planed treatment with other anti-sars cov 2 therapeutics (including but not limited to known anti-sars cov 2 antibodies, small molecule antivirals, etc., other than remdesivir). other conditions that may increase the risk of study participation or, in the investigator's judgment, make the participant inappropriate for the study. have known hypersensitivity to fb2001 or its excipients. any planned vaccine within 28 days following the last administration of fb2001 for injection.

pregnant or breastfeeding, or intending to become pregnant during the study or within 30 days after the final dose or who are not willing to use a highly effective method of contraception. known human immunodeficiency virus (hiv) infection with a viral load greater than 400 copies/ml or cd4 count less than 200 cell/µl. subject with moderate to severe hepatic impairment or acute liver failure. known severe kidney disease. participated in other intervention studies within 6 months. has any condition for which, in the opinion of the investigator, participation would not be in the best interest of the participant or that could prevent, limit, or confound the protocol-specified assessments including but not limited to participants who are not expected to survive longer than 48 hours after randomization, or participants who are expected to require mechanical ventilation within 48 hours after randomization, or participants with a recent history of mechanical ventilation. subjects receiving any medications or substances that are strong inhibitors or inducers of cyp3a within 14 days of randomization. received, ongoing or planed treatment with other anti-sars cov 2 therapeutics (including but not limited to known anti-sars cov 2 antibodies, small molecule antivirals, etc., other than remdesivir). other conditions that may increase the risk of study participation or, in the investigator's judgment, make the participant inappropriate for the study. have known hypersensitivity to fb2001 or its excipients. any planned vaccine within 28 days following the last administration of fb2001 for injection.

pregnant or breastfeeding, or intending to become pregnant during the study or within 30 days after the final dose or who are not willing to use a highly effective method of contraception. known human immunodeficiency virus (hiv) infection with a viral load greater than 400 copies/ml or cd4 count less than 200 cell/µl. subject with moderate to severe hepatic impairment or acute liver failure. known severe kidney disease. participated in other intervention studies within 6 months. has any condition for which, in the opinion of the investigator, participation would not be in the best interest of the participant or that could prevent, limit, or confound the protocol-specified assessments including but not limited to participants who are not expected to survive longer than 48 hours after randomization, or participants who are expected to require mechanical ventilation within 48 hours after randomization, or participants with a recent history of mechanical ventilation. subjects receiving any medications or substances that are strong inhibitors or inducers of cyp3a within 14 days of randomization. received, ongoing or planed treatment with other anti-sars cov 2 therapeutics (including but not limited to known anti-sars cov 2 antibodies, small molecule antivirals, etc., other than remdesivir). other conditions that may increase the risk of study participation or, in the investigator's judgment, make the participant inappropriate for the study. have known hypersensitivity to fb2001 or its excipients. any planned vaccine within 28 days following the last administration of fb2001 for injection.