Twenty-two new cases of circulating vaccine-derived poliovirus type 2 (cVDPV2) have been documented from Yemen, the World Health Organization (WHO) reported. Fourteen of these instances occurred in 2024, distributed across various provinces including Sanaa City, AlDhale, Taiz, and AlBaidah, with illness onsets between August 9th and December 24th, 2024. The remaining eight cases emerged in 2025, primarily in AlBaidah and Sanaa City, with onsets between January 2nd and March 25th. This brings the total cVDPV2 cases for 2025 to 14, affecting Yemen, Djibouti, and Sudan, in contrast to 74 cases in 2024, largely concentrated in Yemen and Somalia.
In other developments, no new wild poliovirus type 1 (WPV1) infections were recorded this week, maintaining the 2025 total at 16, split between Afghanistan and Pakistan. However, four new WPV1 environmental samples, all collected on June 23rd, 2025, were detected in Afghanistan, three from Kandahar and one from Nangarhar. The 2025 environmental sample tally now stands at 405, significantly lower than the 741 documented in 2024.
Eighteen new cVDPV2 environmental samples were also identified. Fourteen of these were from Yemen in 2024, collected between April and September, while four were from 2025 – three from Yemen and one from Somalia. This raises the total cVDPV2 isolates from environmental samples in 2025 to 31, impacting several nations including Djibouti, occupied Palestinian territory, Somalia, Yemen, and Sudan, compared to 63 in 2024.