Figure 2

Immunogenicity and Viremia kinetics following 17DD-YF primary vaccination with different doses (27,476 IU-current; 10,447 IU; 3,013 IU; 587 IU; 158 IU and 31 IU). (A) Anti-YF neutralizing antibody titers (• = current dose and fades for subdoses) were measured by PRNT assay carried out 26–34 days (D30) after primary vaccination, as described in Methods. PRNT antibody titers are expressed in log₁₀ mIU/mL and 2.7 log₁₀ mIU/mL as the cut-off point to segregate seropositive from seronegative samples. Significant seropositivy rates (>95%) are highlighted by gray rectangle. (B) Viremia ( = current dose and fades for subdoses) was quantified by Real-time PCR at D3, D4, D5, D6 and D7 after primary vaccination as described in Methods. Viremia results are expressed in copies/mL. Kinetics profiles equivalent to current dose (27,476 IU) are highlighted by gray rectangle. The peaks of fold changes along the timeline were also taken into account as a relevant feature for equivalence assessment and highlighted by *.