Aden (South24) 

Yemen has seen a significant surge in vaccine-derived polio (cVDPV2) cases in 2024, with 33 cases recorded so far, according to the World Health Organization (WHO).

This figure marks a more than four-fold increase from the previous year, which saw only eight cases.

The WHO Regional Office for the Eastern Mediterranean reported in its weekly bulletin that the rise in cases recorded in Yemen until August 25, 2024, represents a 313% increase compared to last year.

The bulletin indicated that Yemen now leads the region in the number of vaccine-derived polio cases, accounting for 89% of the total cases recorded in the Eastern Mediterranean.

The remaining cases were in Somalia, which recorded three cases, and the occupied Palestinian territories, which recorded a single case in July in Gaza’s Deir Al-Balah district.

Last year, the region recorded just 16 cases, equally divided between Yemen and Somalia, with eight cases each.

The WHO Regional Office for the Eastern Mediterranean encompasses 23 countries, including Jordan, Afghanistan, the United Arab Emirates, Pakistan, Bahrain, Tunisia, Iran, Syria, and Yemen.

Vaccine-derived polio (cVDPV2) is a rare form of polio that can emerge in communities with low vaccination rates. The oral polio vaccine (OPV), widely used in global immunization programs, contains a weakened live poliovirus.

In very rare instances, this weakened virus can mutate, regaining its ability to cause disease and spread among unvaccinated or partially immunized populations.

When such a mutated virus circulates in a community, it can lead to cases of polio known as cVDPV2.

While much less common than wild polio, cVDPV2 poses a significant public health challenge, particularly in regions with fragile public health systems and low vaccination rates.