Fig. 4From: Short- and long-term humoral immune response against Yersinia pestis in plague patients, MadagascarDistribution of plague patients by serological status and time elapsed between disease onset and sampling. High-antibody responders are patients with an OD ≥ 1, and low-antibody responders are patients with an OD < 1. These two groups of patients are seropositive for anti-F1 IgG using ELISA with a threshold value of 0.350Back to article page