Curbing an outbreak of circulating vaccine derived poliovirus type 2 in Dollo Zone, Somali Region, Ethiopia: response to outbreak

Abstract

Introduction: although the oral polio vaccine prevents virus transmission from person to person, it is crucial for poliovirus eradication. The continued use of live attenuated poliovirus poses an ongoing risk of circulating Vaccine Derived Poliovirus-2 (cVDPV2) outbreaks. This study assesses the response to the cVDPV2 outbreak in Dollo Zone, Somali Region, Ethiopia. Methods: after examining and verifying the occurrence of the outbreak, a team was established and prepared by resource mobilization, advocacy, and social mobilization. The group endorsed a four-step vaccination strategy, first the rapid response within 14-days by vaccinating a monovalent oral poliovirus-2 (mOPV2) to all under 5-year children in the Zone. The team further enhanced Supplementary Immunization Activities (SIA) for all under-five children with repeated doses of vaccines. At the same time, the team initiated community-based surveillance of Acute Flaccid Paralysis (AFP). Results: in the rapid-response immunization, an average of 91.4% of 0-11 months old and 90.2% of 12-59 months children were vaccinated. In SIA-1, the team vaccinated an average of 88% and 97%, and in SIA-2, 94.8% and 97.6% of children 0-11 months old and 12-59 months old, respectively. The active community-based surveillance of AFP revealed the existence of the disease in a sporadic form, of which two cases were found in Bokh district. Conclusion: the response to curb the outbreak of cVDPV2 has shown a flow of actions to combat the outbreak. Strengthening and formation of response teams at different levels, resource mobilization, advocacy, and social mobilization are all essential components in maximizing the response to the outbreak.