[Feb. 2, 2023] Though progress has been made against polio, the risk of international spread of circulating vaccine-derived poliovirus type 2 (cVDPV2) remains high, and the situation still warrants a public health emergency of international concern (PHEIC), the World Health Organization (WHO) said today.
The announcement follows a recommendation from the WHO’s polio emergency committee, which met on Jan 25 to discuss the latest developments. The group also noted a wild poliovirus type 3 (WPV3) containment breach at a vaccine manufacturer in the Netherlands, which Dutch researchers detailed today in the latest issue of Eurosurveillance.
Cases down in Afghanistan, Pakistan
The WHO first declared a PHEIC for polio in May 2014 owing to the international spread of wild poliovirus type 1 (WPV1), and its emergency committee—which typically meets every 3 months—has now met 34 times.
In its statement, the emergency committee noted that WPV1 cases in Afghanistan and Pakistan have dropped considerably, but detection of WPV1 in the environment continue, which suggests continuing spread. The committee said only three WPV1 genetic clusters remain, which are in Afghanistan, Africa, and Pakistan, and that genetic diversity of the virus has reduced.