a | In antibody-mediated viral neutralization, neutralizing antibodies binding to the receptor-binding domain (RBD) of the viral spike protein, as well as other domains, prevent virus from docking onto its entry receptor, ACE2. b | In antibody-dependent enhancement of infection, low quality, low quantity, non-neutralizing antibodies bind to virus particles through the Fab domains. Fc receptors (FcRs) expressed on monocytes or macrophages bind to Fc domains of antibodies and facilitate viral entry and infection. c | In antibody-mediated immune enhancement, low quality, low quantity, non-neutralizing antibodies bind to virus particles. Upon engagement by the Fc domains on antibodies, activating FcRs with ITAMs initiate signalling to upregulate pro-inflammatory cytokines and downregulate anti-inflammatory cytokines. Immune complexes and viral RNA in the endosomes can signal through Toll-like receptor 3 (TLR3), TLR7 and/or TLR8 to activate host cells, resulting in immunopathology.