CDC/ACIP [to 23 Jun 2018]

CDC/ACIP [to 23 Jun 2018]

MMWR News Synopsis for June 21, 2018
Strategic Response to an Outbreak of Circulating Vaccine-Derived Poliovirus Type 2 — Syria, 2017–2018
The 2017 circulating vaccine-derived poliovirus type 2 (cVDPV22) outbreak in Syria underscores the risk of emergence of vaccine-derived polioviruses in settings of low oral poliovirus vaccine (OPV) coverage and also demonstrates the effectiveness of targeted vaccination using monovalent OPV type 2 in controlling cVDPV2 outbreaks. In areas with very low oral poliovirus vaccine (OPV) coverage, prolonged transmission of vaccine-associated viruses can lead to the emergence of vaccine-derived polioviruses (VDPVs). In 2017, an outbreak of circulating VDPV type 2 (cVDPV2) occurred in Syria, resulting in 74 cases. Implementation of three rounds of monovalent OPV type 2 campaigns coupled with intensified surveillance interrupted the outbreak. A longstanding humanitarian crisis, precipitated by war and political unrest, has left much of Syria’s population vulnerable to recurrent disease outbreaks, including the recent cVDPV2 outbreak. Subnational gaps in acute flaccid paralysis (AFP) surveillance performance and delays in receiving laboratory results, due to difficulties transporting stool specimens, as a result of the country’s complex humanitarian emergency, contributed to the inability to detect the outbreak earlier.