The effect of antibody concentration on the ability to induce ADE in vitro has been shown for the anti-RSV-F-protein mAb palivizumab and the precursor to nirsevimab (D25, lacking the YTE mutation that increases affinity for FcRn): they induce ADE at low concentrations, whereas they are strongly neutralizing; at high concentrations, infection is blocked. Here, FCGRT is linked to infection.