IgG(6) Treatment(6) therapy(6) fatigue(6) Patient(6) COVID-19(4) Encephalitis(4) Protein(3) approved(3) injection(3) challenge(3) cross-react(3) MONITOR(3) Hospitalization(3) IgG1(3) neuronal(3) reported(3) vaccination.(3) SARS-CoV-2 antibody(3) Antiviral agents(3) positively correlated(3) Activation(3) correlation(3) Anti-inflammatory effects(3) weakness(3) polymorphism(3) recent(3) Cladribine(3) IVIG(3) antigenic peptides(3)