This why we worry and have to complete the task!
In Ukraine, a circulating vaccine-derived poliovirus type 1 (cVDPV1) outbreak has been confirmed. Two cases have been confirmed, with dates of onset of paralysis of 30 June and 7 July. 
 
The genetic similarity between the cases indicates active transmission of cVDPV1. Both are from the Zakarpatskaya oblast, in south-western Ukraine, bordering Romania, Hungary, Slovakia and Poland. Ukraine had been at particular risk of emergence of a cVDPV, due to inadequate vaccination coverage. In 2014, only 50% of children were fully immunized against polio and other vaccine preventable diseases. Discussions are currently ongoing with national health authorities to plan and implement an urgent outbreak response.  
 
News came from WHO in their Wild Polio Virus Update dated 9/2/15
 
In late 2014, 340,000 children in the border area of Syria were vaccinated against polio, measles and medical care was provided to them by RI and our partners.  The immediate response in the Ukraine is a great example of how your donations are allowing us to be prepared to handle these isolated cases of polio that we anticipate will continue to pop up until polio is completely eradicated.   The recent introduction of the IPV vaccine will eliminate the rare cases of  cVDPV1 caused by the oral polio vaccine.  We are truly on track to END POLIO NOW