TABLE 2.

Sensitivity, specificity, PPV, and NPV of ELISA with the designated reference value for neutralization assay for vaccinia virus within a subsample of 152 sera

ELISA OD405No. of NT50 resultsSensitivity (%)Specificity (%)PPV (%)NPV (%)
≥4<4
≥0.109617
97.067.985.092.3
<0.10336
≥0.30887
88.986.892.680.7
<0.301146