The main objectives of the SOPs are to: (i) establish standards and timelines for response activities; and (ii) guide national governments and GPEI partners in key support functions. This new version of the SOPs presents overall response requirements for dealing with type 1, 2 and 3 poliovirus following monovalent type 2 oral polio vaccine (mOPV2) cessation. Version 2.4 will be valid until release of revised version 3.0 (anticipated May 2018).