FIG 4.

Antibody-mediated immune response induced by clones B141 and B388 in immunized mice. BALB/c mice were either mock immunized (PBS) or immunized with 10⁶ PFU of B141 or B388 via tail scarification, and sera were collected 21 days postimmunization. (A) Anti-VACV IgG titers in sera from individual mice were determined by ELISA. Data are presented as mean IgG titers (± standard errors of the means [SEM]) from 2 independent experiments (n = 3 mice per group per experiment). ***, P < 0.001 (one-way ANOVA followed by Tukey's posttest). (B) Detection of MV-neutralizing antibodies by PRNT. Serum dilutions were incubated with VACV-WR followed by infection of BSC-40 cells. Data from 2 independent experiments (n = 3 mice per group per experiment) are presented as the mean percentages (±SEM) of viral plaques relative to control infections in the absence of serum and considered 100%. (C) Detection of EEV-neutralizing antibodies by comet tail inhibition assay. BSC-40 cells were infected with VACV-WR and incubated for 72 h either in the absence or in the presence of pooled sera (1:50) from mock-immunized or immunized mice. Representative images are shown.