Agence France-Presse: Ukraine reports polio outbreak, first cases in Europe since 2010: WHO
“Two polio cases have been confirmed in western Ukraine, the first to be recorded in Europe since 2010, the World Health Organization (WHO) said on Wednesday…” (Savochenko, 9/2).

BBC News: Children paralyzed in Ukraine polio outbreak
“…Both cases were in Ukraine where only half the children are fully immunized. It is likely large numbers of other children have also been infected without developing symptoms…” (Gallagher, 9/2).

The Guardian: Polio in two Ukrainian children first occurrence of disease in Europe since 2010
“…The two cases are vaccine-derived polio. Children are given a weak, attenuated dose of live polio virus when they are vaccinated, which stimulates the immune system and confers immunity. But the weakened virus replicates in the gut for a while and is excreted. If it is able to circulate for some considerable time, it can mutate to a strain capable of causing disease, called a circulating vaccine-derived poliovirus…” (Boseley, 9/2).

New York Times: Polio Paralyzes 2 Children in West Ukraine Outbreak
“…Outbreaks of vaccine-derived virus are usually limited and can be stopped by immunizing children in areas around all known cases. Ukraine has a large supply of polio vaccine on hand and is preparing a vaccination drive, [Hamid Jafari, WHO director of polio eradication,] said…” (McNeil, 9/2).

PBS NewsHour: First polio outbreak since 2010 reported in Europe, WHO says
“…National health authorities are currently in discussion in order to plan and implement a response to the outbreak…” (Harven, 9/2).

Reuters: Ukraine outbreak brings polio back to Europe, WHO says
“…The WHO said Ukraine had been at particular risk of an outbreak because of inadequate vaccination coverage. In 2014, only 50 percent of children were fully immunized against polio and other preventable diseases, it said…” (Miles, 9/2).