Figure 4.

One-way sensitivity analysis net benefits graph for three polio immunization schedules. In (a), NMB of IPV-containing schedules was estimated over cost of IPV (X-axis), while that of the four-tOPV schedule was constant. In (b), NMB of the four-tOPV schedule was estimated over the incidence of VAPP cases with the four-tOPV, and those of IPV-containing schedules remained stable. The WTP in the decision tree model was set as CNY 600,000. NMB = total benefit – total cost, in which total benefit = effectiveness (sum of LY per year) × bound of ICERLY (that is WTP) and total cost was the total annual cost of different polio immunization schedules. bOPV, bivalent live attenuated oral polio vaccine; tOPV, trivalent live attenuated oral polio vaccine; IPV, inactivated polio vaccine; NMB, net monetary benefit; VAPP, vaccine-associated paralytic poliomyelitis.