Intervention: SODIUM CHLORIDE
Trial phase: Phase 3
ATC code: A12CA01 | B05CB01 | B05XA03 | S01XA03
SMILES: [Cl-].[Na+]
Sex: All
Age groups: Adult | Older Adult
Healthy volunteers: No
Participants at risk: 156
Group description: Participants received C19-IG 20% matching placebo as SC infusion containing two syringes of 5 mL each sterile 0.9% NaCl injection on Day 1.
Eligibility criteria:
Inclusion Criteria:

Ambulatory male or female outpatients ≥ 18 years of age who have laboratory-confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection as determined by qualitative PCR (reverse transcriptase (RT)-PCR), or other commercial or public health assay approved by regulatory authorities as a diagnostic test for COVID-19 (inclusive of SARS-CoV-2 antigen testing or other approved rapid testing platforms) in any specimen ≤ 5 days prior to randomized treatment.
Asymptomatic with no constitutional COVID-19 illness (evident symptoms), specifically no fever, cough, shortness of breath, fatigue, anorexia, vomiting/diarrhea, headache that is unrelated to pre-existing conditions (example, migraine), sore throat that is unrelated to other pre-existing medical conditions (example, allergies, gastroesophageal reflux disease), myalgias, olfactory disorders unrelated with previous medical condition, or evidence of pneumonia at Screening.
Pulse oximetry peripheral oxygen saturation (SpO2) (oxygen saturation) on room air > 94% (i.e., 95% to 100%) at Screening.
National Early Warning Score (NEWS) ≤ 2 points at Screening.
Participant provides informed consent (ICF) prior to initiation of any study procedures.

Exclusion Criteria:

Participants who are admitted to hospital or for whom hospital admission is being planned at the time of Screening.
Participants requiring any form of oxygen supplementation at Screening.
Concurrent or planned treatment with other agents with actual or possible direct antiviral activity against SARS-CoV-2 including remdesivir.
Prior, concurrent or planned treatment with monoclonal antibodies (mAbs) against SARS-CoV-2
Have participated in a previous SARS-CoV-2 vaccine study OR outside of a study have received any SARS-CoV-2 vaccine of any kind.
Have a history of convalescent COVID-19 plasma treatment at Screening.
Fever (temperature ≥38.0° C [≥100.4° F]), measured orally, requirement for antipyretics to reduce temperature (administered for fever), and/or respiratory symptoms (cough, dyspnea) at Screening.
Clinical evidence of any significant acute or chronic disease that, in the opinion of the investigator, may place the participant at undue medical risk for study treatment.
The participant has had a known (documented) history of serious anaphylactic reaction to blood, any blood-derived plasma product or commercial immunoglobulin, or has known selective immunoglobulin A (IgA) deficiency with anti-IgA antibodies.
Decompensated congestive heart failure or renal failure with fluid overload. This includes currently uncontrolled congestive heart failure New York Heart Association Class III or IV stage heart failure.
Participants for whom there is limitation of therapeutic effort such as "Do not resuscitate" status.
Currently participating in another interventional clinical trial with investigational medical product or device.
Participants with known (documented) thrombotic complications to polyclonal intravenous immune globulin (IVIG) therapy in the past.
Participant has medical condition (other than COVID-19) that is projected to limit lifespan to ≤ 1 year.
Participant has history of drug or alcohol abuse within the past 12 months.
Participant is unwilling to commit to follow-up visits.

Women who are pregnant or breastfeeding, or if of childbearing potential, unwilling to practice a highly effective method of contraception (oral, injectable, or implanted hormonal methods of contraception, placement of an intrauterine device or intrauterine system, condom, or occlusive cap with spermicidal foam/gel/cream/suppository, male sterilization, or true abstinence) throughout the study.

True abstinence: When this is in line with the preferred and usual lifestyle of the participant. (Periodic abstinence [e.g., calendar, ovulation, symptothermal, post-ovulation methods], declaration of abstinence for the duration of a trial, and withdrawal are not acceptable methods of contraception).
Note: Women who are >55 years and with the absence of menses in the last 12 months are considered to be not of childbearing potential. Female participants of childbearing potential must have a negative test for pregnancy blood or urine human chorionic gonadotropin (hCG)-based assay at Screening/Baseline Visit.