Poliovirus Detections Extend Public Health Emergency of International Concern

The World Health Organization (WHO) today announced that although encouraged by the reported progress, the Committee unanimously agreed that the risk of international spread of poliovirus remains a Public Health Emergency of International Concern (PHEIC) and recommended the extension of Temporary Recommendations for a further three months.  

As of August 25, 2023, only two genetic clusters of WPV1 were identified, compared to three in 2022 and five in 2021.

However, there have been multiple chains of transmission within these two genetic clusters, detected primarily in the endemic zones of Eastern Afghanistan and South KP of Pakistan, including an extreme orphan virus, indicating some gaps in surveillance.

And there is a large pool of unvaccinated "zero dose" children in Afghanistan, which could reintroduce wild-type poliovirus into the southern region.

The also noted suboptimal immunization coverage during campaigns in southeastern Africa, Malawi, Mozambique, Zambia, and Zimbabwe. The nOPV2 vaccine has been deployed over 700 million times in Africa.

Based on the current situation and the reports provided by affected countries, the WHO Director-General accepted the Committee's assessment. It determined that the poliovirus situation continues to constitute a PHEIC.

While poliovirus has been detected in southern New York in 2022 and 2023, no outbreak has been confirmed.

Various polio vaccines are approved and available in August 2023 in the U.S. and globally.