Exploring Safety & Clinical Benefit of Anti-Influenza Immunoglobulin Intravenous in Hospitalized Adults With Influenza A

Inclusion Criteria: * Provision of voluntary informed consent in writing by patient, or legally authorized representative. * Age ≥ 18 years of age. * Locally determined positive influenza A infection (Rapid Antigen (Ag) Test or PCR) from a specimen obtained within 2 days prior to randomization. * Onset of symptoms ≤ 6 days before randomization, defined as when the patient first experienced at least one respiratory symptom or fever. * Hospitalized (or in observation unit) with influenza, with anticipated hospitalization for more than 24 hours and will be/already are receiving antiviral SOC. * Experiencing ≥ 1 respiratory symptom (ex. cough, sore throat, nasal congestion) and ≥ 1 constitutional symptom (ex. headache, myalgia, feverishness or fatigue). * For women of child-bearing potential: willingness to abstain from sexual intercourse or use at least 1 form of hormonal or barrier contraception through Day 60 of the study. * Willingness to have blood and respiratory samples obtained and stored. * National Early Warning Score (NEW score) ≥ 3 at screening. Exclusion Criteria: * Use of any investigational product within the past 30 days prior to screening. * History of hypersensitivity to blood or plasma products (as judged by the site investigator). * History of allergy to latex or rubber. * Known medical history of IgA deficiency. * Pregnancy or lactation. * Medical conditions for which receipt of a 500 mL volume of intravenous fluid may be dangerous to the patient (e.g. decompensated congestive heart failure), based on investigator's medical opinion with careful consideration of lab results. * Liver function: liver function test (LFT) \> 2.5 times upper limit of normal (ULN). * Renal Function: glomerular filtration rate (GFR) \< 60 mL/min/1.73 m2 (age and sex adjusted). * A pre-existing condition or use of a medication that, in the opinion of the site investigator, may place the individual at a substantially increased risk of thrombosis (e.g. cryoglobulinemia, severe refractory hypertriglyceridemia, or clinically significant monoclonal gammopathy). * An opinion of the investigator that it would be unwise to allow participation of the patient in the study (the reason for exclusion of the patient must be documented). * Receiving extracorporeal membrane oxygenation (ECMO). * Anticipated life expectancy of \< 90 days. * Confirmed bacterial pneumonia or any concurrent respiratory viral infection that is not influenza A (ex. respiratory syncytial virus (RSV) infection).