A third mass polio vaccination campaign will be carried out next week in the embattled Gaza Strip, following the further detection of poliovirus in wastewater samples, WHO and UNICEF said in a surprise, joint announcement on Wednesday.

“This campaign follows the recent detection of poliovirus in wastewater samples in Gaza, signaling ongoing circulation in the environment, putting children at risk,” the agencies declared.

The new round follows two successful vaccine rounds last autumn, including one carried out during a brief pause from the height of bitter fighting in northern Gaza.  But while those succeeded in reaching over 95% of children 10 and under who were targeted, it apparently was not enough to wipe out the virus entirely. During the second round, in October, WHO also warned that the inability of vaccine teams to reach children in the northernmost neighborhoods of Gaza such as Jabalia, to which Israel had blocked healthworker access while heavy fighting raged, could create future pockets of vulnerability.

“Pockets of individuals with low or no immunity provide the virus an opportunity to continue spreading and potentially cause disease,” WHO and UNICEF said in the statement. ” The current environment in Gaza, including overcrowding in shelters and severely damaged water, sanitation, and hygiene infrastructure, which facilitates fecal-oral transmission, create ideal conditions for further spread of poliovirus. Extensive population movement consequent to the current ceasefire is likely to exacerbate the spread of poliovirus infection.”

Most of Gaza’s sewage infrastructure – along with homes, schools and other infrastructure, have been destroyed during Israel’s invasion of Gaza and 16 months of fighting with Hamas that followed the bloody Hamas raids 7 October into Israeli communities near the Gaza enclave, that led to 1200 deaths and the capture of some 250 hostages. Over 46,000 Gaza Palestinians have been killed by Israel in the ensuing war.

“No additional polio cases have been reported since a ten-month-old child was paralyzed in August 2024,” the agencies said.  “But the new environmental samples from Deir al Balah and Khan Younis, collected in December 2024 and January 2025, confirm poliovirus transmission. The strain detected is genetically linked to the poliovirus detected in the Gaza Strip in July 2024.”

Cease fire creates better access to areas missed

The six week Israel-Hamas ceasefire, that began on 19 January, has also created a much better opportunity for vaccination teams to reach areas that were missed during the October round.

“In 2024, health workers faced significant challenges accessing certain areas of central, north and south Gaza, which required special coordination to enter during the conflict,” the WHO/UNICEF statement noted. “In inaccessible areas such as Jabalia, Beit Lahiya, and Beit Hanoun where humanitarian pauses for the vaccination campaign were not assured, approximately 7,000 children missed vaccination during the second round. The recent ceasefire means health workers have considerably better access now. ”

It’s also clear that the UN health agencies are moving quickly in order to seize the moment of relative calm. The first six-week ceasefire period ends next weekend.

And it almost fell apart last week when Hamas momentarily said it was pausing release of the next three Israeli hostages – before finally going ahead with their release on Saturday, 15 February, as planned.  This Saturday, Hamas has even speeded up the pace, saying it will release the last of the six living Israeli hostages set to be released in this phase of the deal – instead of the three to which it was committed by the agreement.  The bodies of eight deceased Israeli hostages are also to be released before the initial six-week period of calm ends on March 1 next weekend.  Although the two parties have pledged to preserve the peace as long as negotiations for a second phase are continuing, those talks are expected to be even more complex than the first stage agreement, which took months to reach.

All in all, some 33 Israeli hostages are due to be released in the six-week cease-fire. In exchange for each Israeli released, Israel has been releasing some 30–50 Palestinians held in Israeli jails. Israel has also pulled its forces back from the Netzarim corridor that blocked Palestinian movement from southern to northern Gaza, last autumn, as well as from Gaza’s Rafah cross with Egypt, and allowed a surge of humanitarian aid into Gaza.

However, big question marks remain over the future of the present truce.  After the the next pending hostage releases are completed, Hamas will continue to hold over 58 Israelis, young civilian men and soldiers, less than half of whom may really be alive.  Those remaining hostages will only be released as part of a permanent ceasefire deal. At the same time, Israel’s government has said that it won’t agree to a permanent arrangement that leaves Hamas in power in Gaza – although neither Israel nor Arab mediators have so far come up with an alternative governance plan.

And while there is wide support among the Israeli public for the continuation of the ceasefire so that all hostages are released, government hardliners are pressing for a return to war. To complicate negotiations on a second phase even more, United States President Donald Trump has shocked and alienated both Palestinians and the Arab world with his recent declarations that Gazans should be evacuated so that the area can be turned into a “Riviera” under US control – something that would be illegal under international law.

Against this very uncertain future, next week’s polio campaign will unroll. WHO said all Gaza children under 10 years of age will be targeted with a second, or even a third, polio vaccine:  “The upcoming vaccination campaign aims to reach all children under 10 years of age, including those previously missed, to close immunity gaps and end the outbreak. The use of the oral polio vaccine will help end this outbreak by preventing the spread of the virus. An additional polio vaccination round is planned to be implemented in April.”

It added that “there is no maximum number of times a child should be vaccinated. Each dose gives additional protection which is needed during an active polio outbreak.”

Image Credits: WHO, Middle East Eye , @nabilajamal.