Comparative analysis of IgG subclass responses to vaccination with EBVgp350/220 containing immunogens: EBVgp350/220-F VLPs, UV-EBV and soluble recombinant gp350/220 ED. Serum IgG subclass titers were determined on days 14, 56, 154 and 228 post-vaccination by gp350/220 ED-based ELISA. Immunizations were carried out as described in Figure 4. TNE was the vehicle control. X-axis displays immunogen and date of vaccination. Y-axis indicates antibody titer specific for soluble recombinant gp350/320 ED on a log scale (A) IgG1 (B) IgG2a (C) IgG2b (D) IgG3.