The World Health Organization (WHO) aims to begin a major polio booster vaccination campaign in Gaza next week with the dispatch of over 1.2 million vaccines to the war-torn Palestinian enclave – against a backdrop of spiralling regional tensions.  

WHO director-general Dr Tedros Adhanom Ghebreyesus warned again on Wednesday that the presence of polio virus in wastewater is a “tell-tale” sign that polio is circulating in the war-stricken zone. Unvaccinated children under 5 years are at highest risk for contracting the highly infectious disease, the WHO chief said. 

The agency is now gearing up to vaccinate 600,000 children under 8 in two rounds, beginning Wednesday, August 17, as part of an emergency deployment it first announced on July 26.  

 “There is a high risk of spreading of the circulating vaccine-derived polio virus in Gaza, not only because of the detection but because of the very dire situation with the water sanitation,” said Ayadil Saparbekov, team lead for health emergencies at WHO in Gaza and the West Bank via video link from Jerusalem.

Gaza’s health authority has declared the territory a “polio epidemic zone,” blaming the virus’s presence on Israel’s continued military attacks and the subsequent destruction of health facilities. Israel’s military has begun vaccinating its personnel against polio. 

Only 16 of the territory’s 36 hospitals are partially functional, according to the WHO.

Conflict leaves Gazan children lacking routine immunizations

Before the war, polio immunization rates in Gaza and the Israeli-occupied West Bank approached 99% – considered optimal by the WHO. Rates in Gaza have plummeted in the 10 months since fighting began between Gaza’s Islamic Hamas regime and Israel. 

The WHO said barriers to vaccination include “lack of security, access obstruction, constant population displacement, shortages of medical supplies, poor quality of water and weakened sanitation”. 

Saparbekov described dire sanitary conditions across the enclave, with many people living in shelters with one toilet for 600 people and little access to safe drinking water. 

The polio virus spreads through contact with sewage and feces containing traces of vaccine-derived variants of the live virus. In under-vaccinated groups, the vaccine-derived virus can cause paralysis and sometimes death. 

The fight against polio, considered a crowning achievement in global health, has seen cases plummet by over 99.9% since 1988. The outbreak in Gaza underscores the fragility of this progress.

Conflict causes polio to “thrive”

Tedros said the discovery of polio in Gaza’s wastewater samples amid the destruction isn’t surprising. Recent wars in Syria, Somalia and Afghanistan led to devastating polio outbreaks, paralyzing underimmunized children. Afghanistan and Pakistan, the last two countries with wild polio, continue to struggle with repeated outbreaks due to humanitarian crises. 

“We have seen polio thrive in places hit by conflict and instability,” wrote Dr Tedros in a recent article. 

“[It is] just a matter of time before it reaches the thousands of children who have been left unprotected,” the WHO chief warned.  

Gaza’s decimated health and sanitation systems have set back routine immunizations not just for polio, but also measles, hepatitis A, and meningococcal meningitis. People in the territory are also suffering from high levels of diarrheal diseases, lice, scabies, and skin diseases from the ever-worsening sanitary conditions. 

“The waste management system in Gaza has collapsed,” Philippe Lazzarini, head of the UN agency that assists Palestine, said on Twitter. “Sewage discharges on the streets while people queue for hours just to go to the toilets…make a dangerous recipe for diseases to spread.”

Lack of ceasefire threatens vaccine delivery

Six environmental samples of variant poliovirus type 2 have been detected from Khan Younis and Deir al Balah in #Gaza. No paralytic cases have been detected.
@WHO, the Ministry of Health, @UNICEF, @UNRWA and partners are conducting a risk assessment on the scope of poliovirus…

— Tedros Adhanom Ghebreyesus (@DrTedros) July 19, 2024

Delivering 1.2 million doses of polio vaccines to Gaza’s children is a “huge logistical challenge,” said WHO technical officer Andrea King. Polio vaccines require stable refrigeration – a challenge even in peacetime

The UN reports ongoing obstacles to aid delivery, including “hostilities, unexploded ordnance, damaged and impassable roads, attacks on aid convoys, a lack of public order and safety, and not enough border crossings.”

Dr Tedros emphasized the agency needs “absolute freedom of movement for health workers and medical equipment to carry out these complex operations safely and effectively” in order “to protect children in Gaza from polio.” 

“A ceasefire is essential to allow an effective response,” he said. 

Image Credits: UNRWA , Global Polio Eradication Initiative, UNRWA.