C3 and acute disseminated encephalomyelitis: Finally, the presence of serum complement – such as C1q and C3 - can inhibit IgG mediated ADE both in vitro and in vivo, ostensibly by interfering with the ability of IgG Fc to interact with FcγR and/or forcing a complement-bound antibody into a configuration that is not amenable to fusion and viral entry (46–48).