George Shirreff, Mufti Zubair Wadood, Rui Gama Vaz, Roland W. Sutter, and Nicholas C. Grassly
Figure 1. Effect of mass vaccination campaigns with inactivated poliovirus vaccine plus trivalent oral poliovirus vaccine (IPV+tOPV) or tOPV alone on poliovirus detection in persons or the environment, Nigeria and Pakistan, 2014–2016. The incidence rate ratio for poliomyelitis and the prevalence ratio for poliovirus detection in environmental samples (sewage) during 90 days after compared with 90 days before mass vaccination campaigns are shown for Nigeria (A) and Pakistan (B) and can be compared with the complete data and estimates (Technical Appendix Tables 1, 3). The estimates (diamonds) are shown with 95% CIs (error bars); the dashed error bars indicate when the upper CI exceeded the plot limit of 1.4.