Figure 3. Relative odds of shedding vaccine poliovirus after challenge among individuals vaccinated with IPV compared with unvaccinated individuals.

Labeling as for Figure 2. The χ² test for heterogeneity among studies was not significant for any serotype (p-values 0.11, 0.47, and 0.07) or for the overall odds ratio (p-value 0.10). *Ghendon et al. 1961 [17] compare vaccinated and unvaccinated children who were confirmed seropositive and seronegative, respectively.