Situation Report
Emergency Response
Confirmed cases: Vaccine-derived polio outbreak in Sudan
Vaccine-derived polio outbreak in Sudan, as of 27 August

Humanitarians and Government prepare to vaccinate nearly 9 million children due to ongoing polio outbreak

The Federal Ministry of Health, with support of UNICEF, WHO and WFP, is preparing a mass vaccination campaign to reach every single child under age 5 in Sudan—nearly 9 million children—, following the recent declaration of a vaccine-derived polio outbreak in the country. The immunization against the poliovirus will require around US$20 million to cover logistics, operation and a community engagement campaign. Nearly $5 million of this total will be used to resume and cover gaps of the routine vaccination across the country, seriously compromised during the COVID-19 pandemic.

Declared on 9 August, this is the first polio outbreak in Sudan in more than a decade and has affected nine states across the country. At least 13 cases of circulating vaccine-derived poliovirus have been confirmed in West Darfur, East Darfur, South Darfur, Gedaref, Al Gezira, White Nile, River Nile and Red Sea states. In addition, positive environmental samples of poliovirus type 2 have also been found Khartoum State, indicating a possible wide circulation of the virus within the country.

Although Africa was recently declared free of the wild poliovirus by the African Regional Certification Commission for Polio Eradication, vaccine-derived polio persists and poses a threat to many countries. Neighbouring Ethiopia, Central African Republic and Chad also reported cases, which puts more risks on Sudan, especially in the Darfur region, due to border movements.

Vaccine-derived polio

According to WHO, a vaccine-derived polio outbreak occurs in countries with low levels of immunization and poor sanitation conditions. When a child is immunized against polio, the weakened vaccine-virus replicates in the intestine and can be excreted in the environment. Although sometimes it can even offer protection to other children through ‘passive’ immunization, in some rare cases, after a long period of circulation, the vaccine-virus can genetically change into a form that can paralyze. Circulating vaccine-derived polioviruses must be managed in the same way as wild poliovirus outbreaks.The response must include vaccinating every child under age 5 with to stop transmission.

Read more on the Flash Update:

Vaccine-derived polio outbreak - Flash Update #1 - 13 August 2020