Study of the Efficacy and Safety of Immune Globulin Intravenous (Human) Flebogamma® 5% Dual Inactivation and Filtration (DIF) in Participants With Post-polio Syndrome

Inclusion Criteria: * Participants with Body Mass Index less than 35 kg/m\^2. * Participants who meet the clinical criteria for diagnosis of PPS as set by March-of-Dimes. * Participants who are ambulatory or are able to walk with a cane or other aids or use a wheelchair (but they are not wheelchair-bound). * Participants who have at least 2 newly weakened muscle groups due to PPS (as defined by medical history), with at least 1 of them in a lower extremity, and having a Medical Research Council (MRC) scale score greater than 3 at the Manual Muscle Testing (MMT) performed by the independent assessor at the Screening Visit (SV). * Female of child-bearing potential must have a negative test for pregnancy (Human chorionic gonadotropin (HCG)-based assay). * Female of child-bearing potential and their sexual partners have agreed to practice contraception using a method of proven reliability (i.e., hormonal methods; barrier methods; intrauterine devices methods) to prevent a pregnancy during the course of the clinical trial. * Participants must be willing to comply with all aspects of the clinical trial protocol, including blood sampling and long-term storage of extra samples for the entire duration of the study. * Participants who are able to walk a 2MWD of at least 50 meters at the SV and Enrollment Visit/Infusion Visit 1 (EV/IV1) * Participants who are able to walk a consistent baseline 2 MWD, that is, the difference in 2MWD between the SV and EV/IV1 is not more than 10%. Exclusion Criteria: * Participants who have received human normal immune globulin treatment given by intravenous, subcutaneous, or intramuscular route within the last 3 years. * Participants who are not ambulatory (wheelchair-bound individuals). * Participants with poor venous access. * Participants with intractable pain requiring narcotics or other psychotropic drugs. * Participants with a history of anaphylactic reactions or severe reactions to any blood-derived product. * Participants with a history of intolerance to any component of the investigational products, such as sorbitol. * Participants receiving corticosteroids, except for those who are taking inhaled corticosteroids for asthma. * Participants with a documented diagnosis of hyper viscosity or hypercoagulable state or thrombotic complications to polyclonal intravenous immunoglobulin (IVIG) therapy in the past. * Participants with a history of recent (within the last year) myocardial infarction, stroke, or uncontrolled hypertension. * Participants who suffer from congestive heart failure, embolism, or electrocardiogram changes indicative of unstable angina or atrial fibrillation. * Participants with a history of chronic alcoholism or illicit drug abuse (addiction) in the preceding 12 months prior to the SV. * Participants with active psychiatric illness that interferes with compliance or communication with health care personnel. * Participants with depression with scores \>30 as assessed by the Center for Epidemiologic Studies Depression (CESD) validated scale. * Females who are pregnant or are nursing an infant child. * Participants with any medical condition which makes clinical trial participation unadvisable or which is likely to interfere with the evaluation of the study treatment and/or the satisfactory conduct of the clinical trial according to the Investigator's judgment. * Participants currently receiving, or have received within 3 months prior to the SV, any investigational medicinal product or device. * Participants who are unlikely to adhere to the protocol requirements, or are likely to be uncooperative, or unable to provide a storage serum/plasma sample prior to the first investigational drug infusion. * Participants with known selective Immune globulin A class (IgA) deficiency and serum antibodies anti-IgA. * Participants with renal impairment (i.e., serum creatinine exceeds more than 1.5 times the upper limit of normal \[ULN\]) for the expected normal range for the testing laboratory). * Participants with aspartate aminotransferase (AST) or alanine aminotransferase (ALT) levels exceeding more than 2.5 times the ULN. * Participants with hemoglobin levels \<10 g/dL, platelets levels \<100,000 /mm\^3, white blood cells count \<3.0 k/µL, and erythrocyte sedimentation rate \>50 mm/h or twice above normal. * Participants with known seropositive to Hepatitis C virus (HCV), Human immunodeficiency virus-1 (HIV-1) and/or Human immunodeficiency virus-2 (HIV-2). * Participants with a history of intolerance to fructose.