Validation of quantitative ELISAS for measuring anti-Yersinia pestis F1 and V antibody concentrations in nonhuman primate sera.

This study systematically validated two quantitative enzyme-linked immunosorbent assays (ELISAs) for determining Yersinia pestis anti-F1 or anti-V IgG concentration in cynomolgus macaque sera. The results demonstrated that these ELISAs are reliable, reproducible, and suitable for their intended use to measure both anti-F1 and anti-V IgG in monkey sera following vaccination with a heterologous recombinant fusion F1-V protein (rF1-V). Statistical analysis demonstrated assay precision, accuracy, specificity, linearity/dilutional linearity, and robustness for both assays. The quantitative ranges of standard curves were defined as 40-700 ng/mLfor both anti-F1 and anti-V IgG. Either serological assay could be used to determine potency of F1/V antigen-based vaccines in surrogate clinical studies or to define correlates of protective immunity against plague under the Food and Drug Administration's (FDA) two-animal rule.