At least four cases of polio have been identified in the Democratic Republic of Congo, according to the World Health Organization.

This comes just days after new pledges toward polio eradication were announced at Rotary International’s event in Atlanta.

Read More: WTF Is Polio? 17 Facts About the Disease That We’re This Close to Eradicating

In its disease outbreak update, WHO assessed the risk of national spread of these strains to be high, and the risk of international spread to be medium.

While the news of these cases is not welcome news to the Global Polio Eradication Initiative (GPEI) as polio had been officially eradicated from all but three countries, it's important to note that they are vaccine-derived cases and were not caused by the wild strain of the virus.

WHO reported two separate circulating vaccine-derived poliovirus type 2s (cVDPV2s). The first cVDPV2 strain was found in two districts in Haut-Lomami province and the second cVDPV2 strain was found in two cases in Maniema province.

Vaccine-derived cases like these can occur when the live strain used in the oral vaccine mutates and causes polio.

Read More: Canada Makes $100 Million Pledge for Polio Eradication

Canada announced a contribution of $100 million to the GPEI at the Rotary Convention on Monday. It was just one of many countries and organizations that took part in a pledging moment that resulted in $1.2 billion pledged to end polio.

These are the first cases in DR Congo since 2012. They remind us that contributions worldwide remain important in the fight to eradicate this disease.


Defeat Poverty

New Polio Cases Reported in DR Congo, the First in 5 Years

By Jackie Marchildon