During January 2023–June 2024, 74 circulating vaccine-derived poliovirus outbreaks were detected in 39 countries, resulting in 672 confirmed acute flaccid paralysis cases, predominantly in Africa.
Observational (n=672)
Despite efforts to eradicate polio, 74 cVDPV outbreaks were detected in 39 countries between January 2023 and June 2024, highlighting the need for prompt, high-quality outbreak responses and increased population immunity.
Circulating vaccine-derived polioviruses (cVDPVs) can emerge and lead to outbreaks of paralytic polio as well as asymptomatic transmission in communities with a high percentage of undervaccinated children.Using data from the World Health Organization Polio Information System and Global Polio Laboratory Network, this report describes global polio outbreaks due to cVDPVs during January 2023-June 2024 and updates previous reports.During the reporting period, 74 cVDPV outbreaks were detected in 39 countries or areas (countries), predominantly in Africa.Among these 74 cVDPV outbreaks, 47 (64%) were new outbreaks, detected in 30 (77%) of the 39 countries.Three countries reported cVDPV type 1 (cVDPV1) outbreaks and 38 countries reported cVDPV type 2 (cVDPV2) outbreaks; two of these countries reported cocirculating cVDPV1 and cVDPV2.In the 38 countries with cVDPV2 transmission, 70 distinct outbreaks were reported.In 15 countries, cVDPV transmission has lasted >1 year into 2024.In Nigeria and Somalia, both countries with securitycompromised areas, persistent cVDPV2 transmission has spread to neighboring countries.Delayed implementation of outbreak response campaigns and low-quality campaigns have resulted in further international spread.Countries can control cVDPV outbreaks with timely allocation of resources to implement prompt, high-quality responses after outbreak confirmation.Stopping all cVDPV transmission requires effectively increasing population immunity by overcoming barriers to reaching children.* By genomic sequence analysis of the region encoding capsid viral protein 1, a poliovirus with >1% divergence from the parent Sabin strain for serotypes 1 and 3, or >0.6% for serotype 2, is classified as a vaccine-derived poliovirus (VDPV).Evidence of circulation (i.e., a cVDPV outbreak) occurs when two or more independent detections of genetically linked VDPVs are identified through acute flaccid paralysis (AFP) surveillance, environmental surveillance (ES), or from healthy community members.
Namageyo-Funa et al. (Thu,) conducted a observational in Circulating vaccine-derived poliovirus (cVDPV) outbreaks (n=672). Circulating vaccine-derived poliovirus (cVDPV) was evaluated on Number of cVDPV outbreaks and confirmed acute flaccid paralysis (AFP) cases. During January 2023–June 2024, 74 circulating vaccine-derived poliovirus outbreaks were detected in 39 countries, resulting in 672 confirmed acute flaccid paralysis cases, predominantly in Africa.