FIG. 4.
The nonreplicating viruses induce an efficient humoral immune response of the Th1 phenotype against the recombinant p53 antigen. Mice were immunized once intramuscularly with 106 PFU of the indicated viruses. The vaccinia virion (VV) and the p53-specific antibodies were determined by analysis of a series of serum dilutions in ELISAs using IgG1- and IgG2a-specific antisera for detection. The absolute amounts were determined by plotting against an isotype-specific standard curve. Error bars represent standard deviations. The results are representative of those from three independent experiments.