Figure 4.

Peptide array analysis of Env-specific IgG responses. (A,B) Specificity of serum IgG responses at 14 days after the third and fourth intramuscular immunization (IM) for Group A and B. Shown is the median fluorescence intensity (MFI). IgG responses against individual antigenic regions were considered positive if the corresponding fluorescence intensity was above 2,500 after subtraction of the prevaccination value (D0). The MFI was then calculated for region-specific IgG responses occurring in at least 25% of vaccines. (C) Comparison of total fluorescence intensity of ENV-specific serum antibodies 4 days post third/fourth IM for Group A and B showed no significant differences (Mann–Whitney test).