In summary, the high levels of DENV-1 vaccine induced cross-reactive EDIIFP IgG prior to challenge, increased pathology and mortality, higher viremia, and active viral replication in FcγR bearing cells of WT immunized mice are all consistent with previous descriptions of antibody-enhanced DENV disease in AG129 mice (Balsitis et al., 2010; Zellweger et al., 2010). This evidence concerns the gene FCGR2A and glycogen storage disease VI.