Transmission model calibration.

<p>Each study measured the amount of transmission from index persons in different ways. (A) Houston 1960: fraction of children under 5 years of age shedding each week after mOPV challenge to an index child and subsequent transmission. (Color by subject type; weekly data MLE and 95% CI, dot and whiskers; model MLE and 95% CI, lines). Eight free parameters are jointly identified across the nine calibration targets. (B) Louisiana 1953–1955: incidence in household contacts of index children naturally infected by WPV, measured by seroconversion approximately 30 days after the index child became infected. Three free parameters are jointly identified by the five calibration targets. (C) Uttar Pradesh and Bihar 2003–2008: mean prevalence of WPV in stool measured in household contacts after the onset of paralysis in index children. One free parameter is jointly identified by the two calibration targets. See <a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.2002468#pbio.2002468.s001" target="_blank">S1 Text</a> Fig C for additional information about model fit. CI, confidence interval; MLE, maximum likelihood estimate; mOPV, monovalent OPV; WPV, wild poliovirus.