RU Anti-SARS-CoV-2 (COVID-19) mAbs in Healthy Volunteers

Inclusion Criteria: * Aged 18 or older. * If sexually active male or female, and participating in sexual activity that could lead to pregnancy, agrees to use one effective method of contraception from 10 days prior to the antibody administration until 6 months after investigational product (IP) administration. Exclusion Criteria: * Weight \> 110 kg for groups S1 and S2 only * History of prior positive SARS-CoV-2 RT-PCR or SARS-CoV-2 serology. * Active respiratory or non-respiratory symptoms consistent with COVID-19. * Medically attended acute illness or hospitalization (ie, \>24 hours) for any reason within 30 days prior to screening. * Acute exacerbation of a chronic pulmonary condition (eg, chronic obstructive pulmonary disease \[COPD\], asthma exacerbations, or uncontrolled hypertension, as defined by a systolic blood pressure \> 180 and/or diastolic blood pressure \> 120, in the presence or absence of anti-hypertensive medications) in the past 6 months prior to screening. * Use of systemic corticosteroids, immunosuppressive anti-cancer, or other medications considered significant by the trial physician within the last 6 months. * Other clinically significant acute or chronic medical condition that in the opinion of the investigator would preclude participation. * Laboratory abnormalities in the parameters listed: * Absolute neutrophil count less than 1,500 K/mcL; * Hemoglobin less than 10.5 gm/dL if female; less than 11 gm/dL if male; * Platelet count less than 125,000 K/mcL; * ALT less than 1.25 x ULN; AST less than 1.25 x ULN; * Total bilirubin less than 1.25 x ULN; * Creatinine less than 1.1 x ULN; * Pregnancy or lactation. * Any vaccination within 14 days prior to SARS-CoV-2 mAbs administration (except influenza vaccine). * History of prior receipt of any SARS-CoV-2 vaccine or antibodies, including convalescent plasma. * Known allergy/sensitivity or any hypersensitivity to components of the investigational agents. * History of severe reaction to a vaccine or monoclonal antibody administration or history of severe allergic reactions. * Participation in another clinical study of an investigational product currently or within past 12 weeks, or expected participation during this study.