Two children in Ukraine have been paralysed after contracting polio in the first case of the disease in Europe since 2010.



Confirming the cases in a child of four years and one aged 10 months in Zakarpatskaya oblast, south-west Ukraine, the World Health Organisation’s (WHO) European regional office said it had happened because immunisation rates in the country were extremely low.

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.

If there are high levels of immunisation in the locality, this is unlikely to happen. However, polio immunisation in Ukraine has dropped dramatically since 2008 and there are now vaccine shortages as the country struggles to cope with the conflict with Russia-backed rebels in its east and economic turmoil that has brought it to the brink of bankruptcy.

Last year, less than half (49%) of children were vaccinated. The WHO said in a statement: “Currently, the rate of vaccination against polio among children under a year old is only 14.1%, because of a shortage of vaccine.”

A spokesperson for Unicef said: “Low vaccine coverage in Ukraine was initially triggered by public distrust to immunisation. This was later aggravated by insufficient vaccine supply, due to the financial crisis, and exacerbated by the ongoing conflict and large-scale population displacement in eastern Ukraine.”

Polio vaccine shortages have occurred because of the scale-up of the immunisation programmes around the world in a big push, masterminded by the WHO with the support of the Gates Foundation and Rotary International, to eradicate the disease in the same way as smallpox.

But blitzing the handful of countries where wild poliovirus is still infecting children has absorbed a lot of the vaccine manufacturers’ capacity. Polio is still endemic in Afghanistan and Pakistan. Last year, there were also cases caused by wild poliovirus in Somalia, Equatorial Guinea, Iraq, Cameroon, Syria and Ethiopia. South Sudan had two cases of vaccine-derived polio and Madagascar had one.

There will now be urgent efforts to clamp down on polio in Ukraine. The WHO statement said: “WHO and Unicef are providing the ministry of health with technical and on-site support in planning and implementing large-scale supplementary immunisation activities with oral polio vaccine (OPV) to rapidly stop circulation of the virus.”