Progress Toward Poliomyelitis Eradication - Afghanistan, January 2022-June 2023.

When the Global Polio Eradication Initiative began in 1988, wild poliovirus (WPV) transmission was reported in 125 countries. Since 2017, Afghanistan and Pakistan remain the only countries with uninterrupted endemic WPV type 1 (WPV1) transmission. This report describes activities and progress toward polio eradication in Afghanistan during January 2022-June 2023. Two WPV1 cases were reported during January-December 2022 and five during January-June 2023 (as of August 26), all from three provinces in the southeast and east regions bordering Pakistan. All five 2023 patients had reportedly received ≥16 oral poliovirus vaccine doses. WPV1 was detected in sewage samples from a site in the south region in May 2023 and one in the north region in June 2023, the first detections since February 2021 and March 2020, respectively. Restrictions on house-to-house vaccination limit the effectiveness of vaccination campaigns in parts of the south and northeast regions. Because of population movement, the risk for transmission in Afghanistan and Pakistan will remain if WPV1 circulation continues in either country. Despite operational improvements in vaccination activities, interruption of WPV1 transmission in Afghanistan will require committed, uninterrupted efforts, including ongoing coordination with Pakistan on polio eradication activities, to address vaccination coverage gaps that sustain WPV1 circulation.

Progress Toward Poliomyelitis Eradication - Afghanistan, January 2021-September 2022.

Afghanistan and Pakistan are the two remaining countries with endemic wild poliovirus type 1 (WPV1) transmission (1). During 2019-2020, these countries reported their highest numbers of WPV1 cases since 2014 and experienced outbreaks of type 2 circulating vaccine-derived poliovirus (cVDPV2) (2-4).* In Afghanistan, the number of WPV1 cases nearly doubled, from 29 in 2019 to 56 in 2020; 308 cVDPV2 cases were reported during 2020. After years of active conflict, the Afghanistan government was fully replaced by the Taliban de facto government on August 15, 2021. This report describes activities and progress toward polio eradication in Afghanistan during January 2021-September 2022 and updates previous reports (3,4). During January-December 2021, four WPV1 and 43 cVDPV2 cases were detected, representing decreases of 93% from 56 cases and 86% from 308 cases, respectively, during 2020. During January-September 2022 (reported as of October 20), two WPV1 cases and zero cVDPV2 cases were detected. Although no supplementary immunization activities (SIAs)† occurred during July-October 2021, SIAs resumed during November 2021 in all districts after the political transition, and 3.5-4.5 million previously unreachable persons have been vaccinated since. However, restrictions on how SIAs are conducted are still in place in the critical South Region provinces of Kandahar, Helmand, and Uruzgan. If efforts to vaccinate all children are enhanced and expanded, Afghanistan has an opportunity to interrupt WPV1 transmission during 2023.

Progress Toward Poliomyelitis Eradication - Afghanistan, January 2020-November 2021.

Wild poliovirus types 2 and 3 were declared eradicated in 2015 and 2019, respectively, and, since 2017, transmission of wild poliovirus type 1 (WPV1) has been detected only in Afghanistan and Pakistan. In 2020, these countries reported their highest number of WPV1 cases since 2014 and experienced outbreaks of type 2 circulating vaccine-derived poliovirus (cVDPV2)* (1); in Afghanistan, the number of WPV1 cases reported increased 93%, from 29 in 2019 to 56 in 2020, with 308 cVDPV2 cases reported. This report describes the activities and progress toward polio eradication in Afghanistan during January 2020-November 2021 and updates previous reports (2-4). Despite restrictions imposed by antigovernment elements since 2018, disruption of polio eradication efforts by the COVID-19 pandemic, and civil and political instability, eradication activities have resumed. During January-November 2021, four WPV1 cases and 43 cVDPV2 cases were detected, representing decreases of 93% from 56 and 85% from 281, respectively, during the same period in 2020. After the assumption of nationwide control by the current de facto government of Afghanistan during August 2021, health officials committed to oral poliovirus vaccine (OPV) campaigns nationwide, with the potential to vaccinate approximately 2.5 million children against poliovirus who were previously not accessible for ≥2 years. Although challenges remain, vigorous, sustained polio eradication efforts in Afghanistan could result in substantial progress toward eradication during 2022-2023.