If current efforts to eradicate polioviruses worldwide are successful, then the oral poliovirus vaccine (OPV) currently used for routine immunization in low- and middle-income countries (LMICs) will be replaced by inactivated poliovirus vaccine (IPV). IPV will become the only option for such countries if they want to continue to vaccinate against polio (1). Because IPV is currently considered to be too expensive for use in LMICs, strategies are being undertaken to make IPV more affordable (2). Some experts estimate that…