Pakistan and Afghanistan are the countries in which wild-type polioviruses are transmitted endemic. Among the 110 cases of wild poliovirus throughout the world in 2020, two-thirds were in Pakistan and the remaining one-third were in Afghanistan. In 2014, Pakistan reported 300 cases of paralytic poliovirus; however, it decreased to only one case in 2021. Moreover, health experts are warning about the reemergent of poliovirus in Ukraine amid Russia’s invasion in early 2022. Upon the appearance of several poliovirus vaccine-derived cases in late 2021, the WHO and the health ministry of Ukraine set up a vaccination campaign, but it has been disrupted by war. The resurgence of poliovirus often occurs in unstable areas where health systems are disrupted by war as well as in areas where refugees have resettled. For instance, Syria observed a reemergence of the disease between 2013 to 2014 during the civil war.
2. Where do pockets of Poliovirus infections caused by wildtype polioviruses occur?
