Overcoming barriers to polio eradication in challenging subnational geographies: lessons from South Khyber Pakhtunkhwa, Pakistan, 2022-2024.

The global polio program has relied on supplementary immunization activities (SIA) in countries where routine immunization (RI) coverage is suboptimal. During these SIAs, oral poliovirus vaccine (OPV) is administered to all children under the age of 5 years. However, implementing SIAs in areas with insecurity and conflict, such as the South Khyber Pakhtunkhwa (South KP) region of Pakistan is very challenging because of attacks against vaccination teams and community boycotts among other reasons. These challenges sometimes lead to cancelation, delays, and poor quality of immunization campaigns. We conducted a retrospective secondary data analysis using Pakistan polio program data sourced through National Polio Emergency Operations Center's dashboard, the Expanded Program on Immunization's Management Information System, and the World Health Organization's Immunization Data and Information Management System (IDIMS) to document the different vaccination strategies implemented in the South KP region of Pakistan from January 2022 to December 2024. During this period several SIAs were canceled in the region. In addition, SIAs in South KP were not synchronized with the rest of the province and country, and the duration of these campaigns were sometimes shortened. To address these challenges, several context specific novel interventions were initiated including mobile vaccination teams, ring-fencing vaccination around insecure areas, establishment of permanent transit vaccination points, and closer integration with routine immunization services through targeted use of fractional dose inactivated poliovirus vaccine, identification of zero-dose children during polio SIAs, extended outreaches, and provision of integrated health services through community health camps. Findings from South KP show that strategic alignment between polio and RI programs, flexible operational modalities, and locally responsive engagement can sustain vaccination services despite ongoing insecurity.