inclusion criteria: groups 1a-1d * age 18-65. * sars-cov-2-rna negative naso- or oropharyngeal swab obtained within 3 calendar days before study drug administration by naat (e.g., qrt-pcr). * non-reactivity of serum antibodies (igg; and iga and/or igm when tested) against sars-cov-2 by serological assay at screening. groups 2c-2d * age 18-70. * sars-cov-2-rna positive naso- or oropharyngeal swab obtained within 3 calendar days before study drug administration by naat (e.g., qrt-pcr). * onset of covid-19 symptoms (e.g., sore throat, cough, fever, chills, fatigue, dys- or anosmia, dys- or ageusia, headache, muscle pain, gastrointestinal symptoms) within 7 days prior to study drug administration or non-reactivity of serum or plasma antibodies (igg; and iga and/or igm when tested) against sars-cov-2 by serological assay at screening. * disease severity score 1-4 as defined by the who clinical progression scale (who, lancet inf dis 2020). exclusion criteria (all groups): * known hypersensitivity to any constituent of the investigational medicinal product. * hepatitis b infection indicated by detectable hbsag (hepatitis b surface antigen) in blood. * detectable antibodies against hepatitis c virus in blood unless active hepatitis c is ruled out by negative hcv-rna. * hiv infection indicated by detectable hiv antigen and/or hiv antibodies in blood. * neutrophil count ≤1,000 cells/µl * hemoglobin ≤10 g/dl * platelet count ≤100,000 cells/µl * alt ≥2.0 x uln * ast ≥2.0 x uln * total bilirubin ≥1.5 uln * egfr \<60 ml/min/1.73m2 * pregnancy or lactation. * any vaccination within 14 days prior to dzif-10c administration. * receipt of any sars-cov-2 vaccine or sars-cov-2 monoclonal antibody in the past. * diagnosis of bronchial asthma or history of bronchial hyperresponsiveness, copd, pulmonary fibrosis, or other chronic lung diseases. * any chronic or clinically significant medical condition that in the opinion of investigator would jeopardize the safety or rights of the volunteer. * history of systemic corticosteroids, immunosuppressive anti-cancer, or other medications considered significant by the trial physician within the last 6 months (a single administration of systemic corticosteroids within ≤6 months and ≥4 weeks of enrollment is acceptable). * participation in another clinical trial of an investigational medicinal product within the past 12 weeks or expected participation during this study. * dependency on the principal investigator or study staff; or site personnel directly affiliated with this trial. * legally incapacitated individuals * individuals held in an institution by legal or official order * if engaging in sexual activity that could result in pregnancy, inability or unwillingness to comply with the requirements for highly effective contraception

inclusion criteria: groups 1a-1d * age 18-65. * sars-cov-2-rna negative naso- or oropharyngeal swab obtained within 3 calendar days before study drug administration by naat (e.g., qrt-pcr). * non-reactivity of serum antibodies (igg; and iga and/or igm when tested) against sars-cov-2 by serological assay at screening. groups 2c-2d * age 18-70. * sars-cov-2-rna positive naso- or oropharyngeal swab obtained within 3 calendar days before study drug administration by naat (e.g., qrt-pcr). * onset of covid-19 symptoms (e.g., sore throat, cough, fever, chills, fatigue, dys- or anosmia, dys- or ageusia, headache, muscle pain, gastrointestinal symptoms) within 7 days prior to study drug administration or non-reactivity of serum or plasma antibodies (igg; and iga and/or igm when tested) against sars-cov-2 by serological assay at screening. * disease severity score 1-4 as defined by the who clinical progression scale (who, lancet inf dis 2020). exclusion criteria (all groups): * known hypersensitivity to any constituent of the investigational medicinal product. * hepatitis b infection indicated by detectable hbsag (hepatitis b surface antigen) in blood. * detectable antibodies against hepatitis c virus in blood unless active hepatitis c is ruled out by negative hcv-rna. * hiv infection indicated by detectable hiv antigen and/or hiv antibodies in blood. * neutrophil count ≤1,000 cells/µl * hemoglobin ≤10 g/dl * platelet count ≤100,000 cells/µl * alt ≥2.0 x uln * ast ≥2.0 x uln * total bilirubin ≥1.5 uln * egfr \<60 ml/min/1.73m2 * pregnancy or lactation. * any vaccination within 14 days prior to dzif-10c administration. * receipt of any sars-cov-2 vaccine or sars-cov-2 monoclonal antibody in the past. * diagnosis of bronchial asthma or history of bronchial hyperresponsiveness, copd, pulmonary fibrosis, or other chronic lung diseases. * any chronic or clinically significant medical condition that in the opinion of investigator would jeopardize the safety or rights of the volunteer. * history of systemic corticosteroids, immunosuppressive anti-cancer, or other medications considered significant by the trial physician within the last 6 months (a single administration of systemic corticosteroids within ≤6 months and ≥4 weeks of enrollment is acceptable). * participation in another clinical trial of an investigational medicinal product within the past 12 weeks or expected participation during this study. * dependency on the principal investigator or study staff; or site personnel directly affiliated with this trial. * legally incapacitated individuals * individuals held in an institution by legal or official order * if engaging in sexual activity that could result in pregnancy, inability or unwillingness to comply with the requirements for highly effective contraception

inclusion criteria: groups 1a-1d - age 18-65. - sars-cov-2-rna negative naso- or oropharyngeal swab obtained within 3 calendar days before study drug administration by naat (e.g., qrt-pcr). - non-reactivity of serum antibodies (igg; and iga and/or igm when tested) against sars-cov-2 by serological assay at screening. groups 2c-2d - age 18-70. - sars-cov-2-rna positive naso- or oropharyngeal swab obtained within 3 calendar days before study drug administration by naat (e.g., qrt-pcr). - onset of covid-19 symptoms (e.g., sore throat, cough, fever, chills, fatigue, dys- or anosmia, dys- or ageusia, headache, muscle pain, gastrointestinal symptoms) within 7 days prior to study drug administration or non-reactivity of serum or plasma antibodies (igg; and iga and/or igm when tested) against sars-cov-2 by serological assay at screening. - disease severity score 1-4 as defined by the who clinical progression scale (who, lancet inf dis 2020). exclusion criteria (all groups): - known hypersensitivity to any constituent of the investigational medicinal product. - hepatitis b infection indicated by detectable hbsag (hepatitis b surface antigen) in blood. - detectable antibodies against hepatitis c virus in blood unless active hepatitis c is ruled out by negative hcv-rna. - hiv infection indicated by detectable hiv antigen and/or hiv antibodies in blood. - neutrophil count ≤1,000 cells/µl - hemoglobin ≤10 g/dl - platelet count ≤100,000 cells/µl - alt ≥2.0 x uln - ast ≥2.0 x uln - total bilirubin ≥1.5 uln - egfr <60 ml/min/1.73m2 - pregnancy or lactation. - any vaccination within 14 days prior to dzif-10c administration. - receipt of any sars-cov-2 vaccine or sars-cov-2 monoclonal antibody in the past. - diagnosis of bronchial asthma or history of bronchial hyperresponsiveness, copd, pulmonary fibrosis, or other chronic lung diseases. - any chronic or clinically significant medical condition that in the opinion of investigator would jeopardize the safety or rights of the volunteer. - history of systemic corticosteroids, immunosuppressive anti-cancer, or other medications considered significant by the trial physician within the last 6 months (a single administration of systemic corticosteroids within ≤6 months and ≥4 weeks of enrollment is acceptable). - participation in another clinical trial of an investigational medicinal product within the past 12 weeks or expected participation during this study. - dependency on the principal investigator or study staff; or site personnel directly affiliated with this trial. - legally incapacitated individuals - individuals held in an institution by legal or official order - if engaging in sexual activity that could result in pregnancy, inability or unwillingness to comply with the requirements for highly effective contraception

inclusion criteria: groups 1a-1d - age 18-65. - sars-cov-2-rna negative naso- or oropharyngeal swab obtained within 3 calendar days before study drug administration by naat (e.g., qrt-pcr). - non-reactivity of serum antibodies (igg; and iga and/or igm when tested) against sars-cov-2 by serological assay at screening. groups 2c-2d - age 18-70. - sars-cov-2-rna positive naso- or oropharyngeal swab obtained within 3 calendar days before study drug administration by naat (e.g., qrt-pcr). - onset of covid-19 symptoms (e.g., sore throat, cough, fever, chills, fatigue, dys- or anosmia, dys- or ageusia, headache, muscle pain, gastrointestinal symptoms) within 7 days prior to study drug administration or non-reactivity of serum or plasma antibodies (igg; and iga and/or igm when tested) against sars-cov-2 by serological assay at screening. - disease severity score 1-4 as defined by the who clinical progression scale (who, lancet inf dis 2020). exclusion criteria (all groups): - known hypersensitivity to any constituent of the investigational medicinal product. - hepatitis b infection indicated by detectable hbsag (hepatitis b surface antigen) in blood. - detectable antibodies against hepatitis c virus in blood unless active hepatitis c is ruled out by negative hcv-rna. - hiv infection indicated by detectable hiv antigen and/or hiv antibodies in blood. - neutrophil count ≤1,000 cells/µl - hemoglobin ≤10 g/dl - platelet count ≤100,000 cells/µl - alt ≥2.0 x uln - ast ≥2.0 x uln - total bilirubin ≥1.5 uln - egfr <60 ml/min/1.73m2 - pregnancy or lactation. - any vaccination within 14 days prior to dzif-10c administration. - receipt of any sars-cov-2 vaccine or sars-cov-2 monoclonal antibody in the past. - diagnosis of bronchial asthma or history of bronchial hyperresponsiveness, copd, pulmonary fibrosis, or other chronic lung diseases. - any chronic or clinically significant medical condition that in the opinion of investigator would jeopardize the safety or rights of the volunteer. - history of systemic corticosteroids, immunosuppressive anti-cancer, or other medications considered significant by the trial physician within the last 6 months (a single administration of systemic corticosteroids within ≤6 months and ≥4 weeks of enrollment is acceptable). - participation in another clinical trial of an investigational medicinal product within the past 12 weeks or expected participation during this study. - dependency on the principal investigator or study staff; or site personnel directly affiliated with this trial. - legally incapacitated individuals - individuals held in an institution by legal or official order - if engaging in sexual activity that could result in pregnancy, inability or unwillingness to comply with the requirements for highly effective contraception

inclusion criteria: groups 1a-1c - age 18-65 - sars-cov-2-rna negative in naso- or oropharyngeal swab obtained within 72 hours before study drug administration by qrt-pcr. - non-reactivity of serum antibodies (igg, and iga and/or igm when tested) against sars-cov-2 by serological assay groups 2c-2d - age 18-70 - sars-cov-2-rna positive in naso- or oropharyngeal swab obtained within 72 hours before study drug administration by qrt-pcr. - non-reactivity of serum antibodies (igm and igg or iga and igg) against sars-cov- 2 by serological assay - disease severity 1-3 as defined by who r&d blueprint ordinal scale (february 18, 2020)

inclusion criteria: groups 1a-1c - age 18-65 - sars-cov-2-rna negative in naso- or oropharyngeal swab obtained within 72 hours before study drug administration by qrt-pcr. - non-reactivity of serum antibodies (igg, and iga and/or igm when tested) against sars-cov-2 by serological assay groups 2c-2d - age 18-70 - sars-cov-2-rna positive in naso- or oropharyngeal swab obtained within 72 hours before study drug administration by qrt-pcr. - non-reactivity of serum antibodies (igm and igg or iga and igg) against sars-cov- 2 by serological assay - disease severity 1-3 as defined by who r&d blueprint ordinal scale (february 18, 2020)