Table 4 Estimated threshold for salivary IgG, true positive rate (TPR), false positive rate (FPR), positive predictive value (PPV) and negative predictive value (NPV) with ROC curve analysis with a functional antibody titer (rSBA) >=128 as correlate of protection

From: Use of saliva to monitor meningococcal vaccine responses: proposing a threshold in saliva as surrogate of protection