1. use of any investigational product, within 30 days prior to screening, or use of investigational sars-cov-2 vaccines, sars-cov-2 monoclonal antibodies or covid-19 convalescent plasma at any time prior to screening or during the study follow-up period, or subject plans to participate in another clinical study during the study period. 2. screening clinical laboratory test result greater than the laboratory's upper limit of normal (uln) for alanine aminotransferase (alt), aspartate aminotransferase (ast), random glucose, total and/or bilirubin, blood urea nitrogen (bun), or creatinine. other serum chemistry parameters that are not within the reference range will not be considered exclusionary unless deemed clinically significant by the principal investigator. 3. history of allergy or hypersensitivity to blood or plasma products or to covid-higiv excipients (proline, ps80). 4. history of allergy to latex or rubber. 5. history of hemolytic anemia. 6. history of immunoglobulin a (iga) deficiency. 7. receipt of any blood product within the past 12 months. 8. plasma donation within 7 days or significant blood loss or blood donation within 56 days of randomization/dosing. 9. history of known congenital or acquired immunodeficiency or receipt of immunosuppressive therapy (e.g., prednisone or equivalent for more than two consecutive weeks within the past three months). 10. history of thrombosis or hypercoagulable state with increased risk of thrombosis. 11. history of clinically significant chronic illness (e.g., requiring hospitalization in the past three months) such as cardiac, pulmonary, renal, hepatic or other chronic conditions. 12. receipt of a live vaccine within 28 days prior to screening or anticipated receipt of a live vaccine during the study period. 13. currently pregnant, breastfeeding, or planning to become pregnant during the study. 14. history of, or suspected substance abuse problem (including alcohol). 15. other medical condition which may place subject at increased risk due to participation in the study as determined by the investigator. 16. any planned elective surgery during the study period. 17. an opinion of the investigator that it would be unwise to allow the individual to be randomized into the study.

1. use of any investigational product, within 30 days prior to screening, or use of investigational sars-cov-2 vaccines, sars-cov-2 monoclonal antibodies or covid-19 convalescent plasma at any time prior to screening or during the study follow-up period, or subject plans to participate in another clinical study during the study period. 2. screening clinical laboratory test result greater than the laboratory's upper limit of normal (uln) for alanine aminotransferase (alt), aspartate aminotransferase (ast), random glucose, total and/or bilirubin, blood urea nitrogen (bun), or creatinine. other serum chemistry parameters that are not within the reference range will not be considered exclusionary unless deemed clinically significant by the principal investigator. 3. history of allergy or hypersensitivity to blood or plasma products or to covid-higiv excipients (proline, ps80). 4. history of allergy to latex or rubber. 5. history of hemolytic anemia. 6. history of immunoglobulin a (iga) deficiency. 7. receipt of any blood product within the past 12 months. 8. plasma donation within 7 days or significant blood loss or blood donation within 56 days of randomization/dosing. 9. history of known congenital or acquired immunodeficiency or receipt of immunosuppressive therapy (e.g., prednisone or equivalent for more than two consecutive weeks within the past three months). 10. history of thrombosis or hypercoagulable state with increased risk of thrombosis. 11. history of clinically significant chronic illness (e.g., requiring hospitalization in the past three months) such as cardiac, pulmonary, renal, hepatic or other chronic conditions. 12. receipt of a live vaccine within 28 days prior to screening or anticipated receipt of a live vaccine during the study period. 13. currently pregnant, breastfeeding, or planning to become pregnant during the study. 14. history of, or suspected substance abuse problem (including alcohol). 15. other medical condition which may place subject at increased risk due to participation in the study as determined by the investigator. 16. any planned elective surgery during the study period. 17. an opinion of the investigator that it would be unwise to allow the individual to be randomized into the study.

use of any investigational product, within 30 days prior to screening, or use of investigational sars-cov-2 vaccines, sars-cov-2 monoclonal antibodies or covid-19 convalescent plasma at any time prior to screening or during the study follow-up period, or subject plans to participate in another clinical study during the study period. screening clinical laboratory test result greater than the laboratory's upper limit of normal (uln) for alanine aminotransferase (alt), aspartate aminotransferase (ast), random glucose, total and/or bilirubin, blood urea nitrogen (bun), or creatinine. other serum chemistry parameters that are not within the reference range will not be considered exclusionary unless deemed clinically significant by the principal investigator. history of allergy or hypersensitivity to blood or plasma products or to covid-higiv excipients (proline, ps80). history of allergy to latex or rubber. history of hemolytic anemia. history of immunoglobulin a (iga) deficiency. receipt of any blood product within the past 12 months. plasma donation within 7 days or significant blood loss or blood donation within 56 days of randomization/dosing. history of known congenital or acquired immunodeficiency or receipt of immunosuppressive therapy (e.g., prednisone or equivalent for more than two consecutive weeks within the past three months). history of thrombosis or hypercoagulable state with increased risk of thrombosis. history of clinically significant chronic illness (e.g., requiring hospitalization in the past three months) such as cardiac, pulmonary, renal, hepatic or other chronic conditions. receipt of a live vaccine within 28 days prior to screening or anticipated receipt of a live vaccine during the study period. currently pregnant, breastfeeding, or planning to become pregnant during the study. history of, or suspected substance abuse problem (including alcohol). other medical condition which may place subject at increased risk due to participation in the study as determined by the investigator. any planned elective surgery during the study period. an opinion of the investigator that it would be unwise to allow the individual to be randomized into the study.

use of any investigational product, within 30 days prior to screening, or use of investigational sars-cov-2 vaccines, sars-cov-2 monoclonal antibodies or covid-19 convalescent plasma at any time prior to screening or during the study follow-up period, or subject plans to participate in another clinical study during the study period. screening clinical laboratory test result greater than the laboratory's upper limit of normal (uln) for alanine aminotransferase (alt), aspartate aminotransferase (ast), random glucose, total and/or bilirubin, blood urea nitrogen (bun), or creatinine. other serum chemistry parameters that are not within the reference range will not be considered exclusionary unless deemed clinically significant by the principal investigator. history of allergy or hypersensitivity to blood or plasma products or to covid-higiv excipients (proline, ps80). history of allergy to latex or rubber. history of hemolytic anemia. history of immunoglobulin a (iga) deficiency. receipt of any blood product within the past 12 months. plasma donation within 7 days or significant blood loss or blood donation within 56 days of randomization/dosing. history of known congenital or acquired immunodeficiency or receipt of immunosuppressive therapy (e.g., prednisone or equivalent for more than two consecutive weeks within the past three months). history of thrombosis or hypercoagulable state with increased risk of thrombosis. history of clinically significant chronic illness (e.g., requiring hospitalization in the past three months) such as cardiac, pulmonary, renal, hepatic or other chronic conditions. receipt of a live vaccine within 28 days prior to screening or anticipated receipt of a live vaccine during the study period. currently pregnant, breastfeeding, or planning to become pregnant during the study. history of, or suspected substance abuse problem (including alcohol). other medical condition which may place subject at increased risk due to participation in the study as determined by the investigator. any planned elective surgery during the study period. an opinion of the investigator that it would be unwise to allow the individual to be randomized into the study.

use of any investigational product, within 30 days prior to screening, or use of investigational sars-cov-2 vaccines, sars-cov-2 monoclonal antibodies or covid-19 convalescent plasma at any time prior to screening or during the study follow-up period, or subject plans to participate in another clinical study during the study period. screening clinical laboratory test result greater than the laboratory's upper limit of normal (uln) for alanine aminotransferase (alt), aspartate aminotransferase (ast), random glucose, total and/or bilirubin, blood urea nitrogen (bun), or creatinine. other serum chemistry parameters that are not within the reference range will not be considered exclusionary unless deemed clinically significant by the principal investigator. history of allergy or hypersensitivity to blood or plasma products or to covid-higiv excipients (proline, ps80). history of allergy to latex or rubber. history of hemolytic anemia. history of iga deficiency. receipt of any blood product within the past 12 months. plasma donation within 7 days or significant blood loss or blood donation within 56 days of randomization/dosing. history of known congenital or acquired immunodeficiency or receipt of immunosuppressive therapy (e.g., prednisone or equivalent for more than two consecutive weeks within the past three months). history of thrombosis or hypercoagulable state with increased risk of thrombosis. history of clinically significant chronic illness (e.g., requiring hospitalization in the past three months) such as cardiac, pulmonary, renal, hepatic or other chronic conditions. receipt of a live vaccine within 28 days prior to screening or anticipated receipt of a live vaccine during the study period. currently pregnant, breastfeeding, or planning to become pregnant during the study. history of, or suspected substance abuse problem (including alcohol). other medical condition which may place subject at increased risk due to participation in the study as determined by the investigator. any planned elective surgery during the study period. an opinion of the investigator that it would be unwise to allow the individual to be randomized into the study.

use of any investigational product, within 30 days prior to screening, or use of investigational sars-cov-2 vaccines, sars-cov-2 monoclonal antibodies or covid-19 convalescent plasma at any time prior to screening or during the study follow-up period, or subject plans to participate in another clinical study during the study period. screening clinical laboratory test result greater than the laboratory's upper limit of normal (uln) for alanine aminotransferase (alt), aspartate aminotransferase (ast), random glucose, total and/or bilirubin, blood urea nitrogen (bun), or creatinine. other serum chemistry parameters that are not within the reference range will not be considered exclusionary unless deemed clinically significant by the principal investigator. history of allergy or hypersensitivity to blood or plasma products or to covid-higiv excipients (proline, ps80). history of allergy to latex or rubber. history of hemolytic anemia. history of iga deficiency. receipt of any blood product within the past 12 months. plasma donation within 7 days or significant blood loss or blood donation within 56 days of randomization/dosing. history of known congenital or acquired immunodeficiency or receipt of immunosuppressive therapy (e.g., prednisone or equivalent for more than two consecutive weeks within the past three months). history of thrombosis or hypercoagulable state with increased risk of thrombosis. history of clinically significant chronic illness (e.g., requiring hospitalization in the past three months) such as cardiac, pulmonary, renal, hepatic or other chronic conditions. receipt of a live vaccine within 28 days prior to screening or anticipated receipt of a live vaccine during the study period. currently pregnant, breastfeeding, or planning to become pregnant during the study. history of, or suspected substance abuse problem (including alcohol). other medical condition which may place subject at increased risk due to participation in the study as determined by the investigator. any planned elective surgery during the study period. an opinion of the investigator that it would be unwise to allow the individual to be randomized into the study.

1. use of any investigational product, within 30 days prior to screening, or use of investigational sars-cov-2 vaccines, sars-cov-2 monoclonal antibodies or covid-19 convalescent plasma at any time prior to screening or during the study follow-up period, or subject plans to participate in another clinical study during the study period. 2. screening clinical laboratory test result greater than the laboratory's upper limit of normal (uln) for alanine aminotransferase (alt), aspartate aminotransferase (ast), random glucose, total and/or bilirubin, blood urea nitrogen (bun), or creatinine. other serum chemistry parameters that are not within the reference range will not be considered exclusionary unless deemed clinically significant by the principal investigator. 3. history of allergy or hypersensitivity to blood or plasma products or to covid-higiv excipients (proline, ps80). 4. history of allergy to latex or rubber. 5. history of hemolytic anemia. 6. history of iga deficiency. 7. receipt of any blood product within the past 12 months. 8. plasma donation within 7 days or significant blood loss or blood donation within 56 days of randomization/dosing. 9. history of known congenital or acquired immunodeficiency or receipt of immunosuppressive therapy (e.g., prednisone or equivalent for more than two consecutive weeks within the past three months). 10. history of thrombosis or hypercoagulable state with increased risk of thrombosis. 11. history of clinically significant chronic illness (e.g., requiring hospitalization in the past three months) such as cardiac, pulmonary, renal, hepatic or other chronic conditions. 12. receipt of a live vaccine within 28 days prior to screening or anticipated receipt of a live vaccine during the study period. 13. currently pregnant, breastfeeding, or planning to become pregnant during the study. 14. history of, or suspected substance abuse problem (including alcohol). 15. other medical condition which may place subject at increased risk due to participation in the study as determined by the investigator. 16. any planned elective surgery during the study period. 17. an opinion of the investigator that it would be unwise to allow the individual to be randomized into the study.

1. use of any investigational product, within 30 days prior to screening, or use of investigational sars-cov-2 vaccines, sars-cov-2 monoclonal antibodies or covid-19 convalescent plasma at any time prior to screening or during the study follow-up period, or subject plans to participate in another clinical study during the study period. 2. screening clinical laboratory test result greater than the laboratory's upper limit of normal (uln) for alanine aminotransferase (alt), aspartate aminotransferase (ast), random glucose, total and/or bilirubin, blood urea nitrogen (bun), or creatinine. other serum chemistry parameters that are not within the reference range will not be considered exclusionary unless deemed clinically significant by the principal investigator. 3. history of allergy or hypersensitivity to blood or plasma products or to covid-higiv excipients (proline, ps80). 4. history of allergy to latex or rubber. 5. history of hemolytic anemia. 6. history of iga deficiency. 7. receipt of any blood product within the past 12 months. 8. plasma donation within 7 days or significant blood loss or blood donation within 56 days of randomization/dosing. 9. history of known congenital or acquired immunodeficiency or receipt of immunosuppressive therapy (e.g., prednisone or equivalent for more than two consecutive weeks within the past three months). 10. history of thrombosis or hypercoagulable state with increased risk of thrombosis. 11. history of clinically significant chronic illness (e.g., requiring hospitalization in the past three months) such as cardiac, pulmonary, renal, hepatic or other chronic conditions. 12. receipt of a live vaccine within 28 days prior to screening or anticipated receipt of a live vaccine during the study period. 13. currently pregnant, breastfeeding, or planning to become pregnant during the study. 14. history of, or suspected substance abuse problem (including alcohol). 15. other medical condition which may place subject at increased risk due to participation in the study as determined by the investigator. 16. any planned elective surgery during the study period. 17. an opinion of the investigator that it would be unwise to allow the individual to be randomized into the study.

1. use of any investigational product, within 30 days prior to screening, or use of investigational sars-cov-2 vaccines, sars-cov-2 monoclonal antibodies or covid-19 convalescent plasma at any time prior to screening or during the study follow-up period, or subject plans to participate in another clinical study during the study period. 2. screening clinical laboratory test result greater than the laboratory's upper limit of normal (uln) for alanine aminotransferase (alt), aspartate aminotransferase (ast), random glucose, total and/or bilirubin, blood urea nitrogen (bun), or creatinine. other serum chemistry parameters that are not within the reference range will not be considered exclusionary unless deemed clinically significant by the principal investigator. 3. history of allergy or hypersensitivity to blood or plasma products or to covid-higiv excipients (proline, ps80). 4. history of allergy to latex or rubber. 5. history of hemolytic anemia. 6. history of iga deficiency. 7. receipt of any blood product within the past 12 months. 8. plasma donation within 7 days or significant blood loss or blood donation within 56 days of randomization/dosing. 9. history of known congenital or acquired immunodeficiency or receipt of immunosuppressive therapy (e.g., prednisone or equivalent for more than two consecutive weeks within the past three months). 10. history of thrombosis or hypercoagulable state with increased risk of thrombosis. 11. history of clinically significant chronic illness (e.g., requiring hospitalization in the past three months) such as cardiac, pulmonary, renal, hepatic or other chronic conditions. 12. receipt of a live vaccine within 28 days prior to screening or anticipated receipt of a live vaccine during the study period. 13. currently pregnant, breastfeeding, or planning to become pregnant during the study. 14. history of, or suspected substance abuse problem (including alcohol). 15. failure of urine drug test at screening. 16. other medical condition which may place subject at increased risk due to participation in the study as determined by the investigator. 17. any planned elective surgery during the study period. 18. an opinion of the investigator that it would be unwise to allow the individual to be randomized into the study.

1. use of any investigational product, within 30 days prior to screening, or use of investigational sars-cov-2 vaccines, sars-cov-2 monoclonal antibodies or covid-19 convalescent plasma at any time prior to screening or during the study follow-up period, or subject plans to participate in another clinical study during the study period. 2. screening clinical laboratory test result greater than the laboratory's upper limit of normal (uln) for alanine aminotransferase (alt), aspartate aminotransferase (ast), random glucose, total and/or bilirubin, blood urea nitrogen (bun), or creatinine. other serum chemistry parameters that are not within the reference range will not be considered exclusionary unless deemed clinically significant by the principal investigator. 3. history of allergy or hypersensitivity to blood or plasma products or to covid-higiv excipients (proline, ps80). 4. history of allergy to latex or rubber. 5. history of hemolytic anemia. 6. history of iga deficiency. 7. receipt of any blood product within the past 12 months. 8. plasma donation within 7 days or significant blood loss or blood donation within 56 days of randomization/dosing. 9. history of known congenital or acquired immunodeficiency or receipt of immunosuppressive therapy (e.g., prednisone or equivalent for more than two consecutive weeks within the past three months). 10. history of thrombosis or hypercoagulable state with increased risk of thrombosis. 11. history of clinically significant chronic illness (e.g., requiring hospitalization in the past three months) such as cardiac, pulmonary, renal, hepatic or other chronic conditions. 12. receipt of a live vaccine within 28 days prior to screening or anticipated receipt of a live vaccine during the study period. 13. currently pregnant, breastfeeding, or planning to become pregnant during the study. 14. history of, or suspected substance abuse problem (including alcohol). 15. failure of urine drug test at screening. 16. other medical condition which may place subject at increased risk due to participation in the study as determined by the investigator. 17. any planned elective surgery during the study period. 18. an opinion of the investigator that it would be unwise to allow the individual to be randomized into the study.