FIG 8.

Anamnestic immune response following challenge. On days 71 (A) and 77 (B) postvaccination (days 9 and 15 postchallenge), we looked for evidence of a memory immune response by measuring the fold increase in IgG in animals given HR-Tet prior to challenge compared to IgG in mock-vaccinated animals. An anamnestic response was defined as any response ≥4-fold greater than that of the naive unchallenged control. Animals given HR-Tet prior to challenge with one of the four serotypes of DENV developed a memory immune response against all four serotypes starting at 9 days postchallenge (A, gray bars), and this memory response continued out to 15 days postchallenge (B, gray bars). No evidence of a memory response was seen in mock-vaccinated animals following challenge at either time point (A and B, hatched bars).