Figure 2: Indirect IgG ELISA titers for recognition of recombinant antigens; Infected sera were collected and pooled on 22nd day Y. pestis post challenge mice and for negative control Pre-infected sera were used. The Recombinant antigens [A] YopH; [B] YopM; [C] V antigen; [D] Pla; [E] YopE and [F] F1were tested for recognition at twofold dilution by ELISA.