FIG. 2.

(A) Viremia in monkeys inoculated with DEN1 vaccine candidates. Groups of four rhesus monkeys were inoculated subcutaneously with 5.0 log₁₀ PFU of the indicated virus in a 1-ml dose. Serum was collected daily, and virus titers were determined by plaque assays in Vero cells. Mean virus titers are shown for monkeys in each group. The lower level of virus detection was 0.7 log₁₀ PFU/ml. (B) For comparison, viremia levels in monkeys inoculated previously with vaccine candidate rDEN4Δ30 (6) are shown. Groups of four monkeys were inoculated in a manner identical to that described above.