The World Health Organization has announced it has “a preliminary commitment” for humanitarian pauses in fighting in the Gaza Strip to allow for the vaccination of children against polio, with the first vaccinations to begin as early as this weekend. The UN is preparing to vaccinate an estimated 640,000 children in Gaza, where the UN’s global health body confirmed on 23 August that at least one baby has been paralysed by the type 2 polio virus, the first such case in the territory in 25 years. The WHO’s announcement follows earlier indications by Israel’s prime minister, Benjamin Netanyahu, who had suggested there could be a part suspension of military operations in Gaza to allow young children to be vaccinated against the disease. A WHO official said that the planned vaccination campaign would be completed in phases over three days each in specific zones where there would be a cessation in the fighting to allow the programme to take place, with an option to extend the vaccination by a day if necessary. In a statement, Netanyahu’s office denied an Israeli television report that there would be a general truce during the vaccination campaign, which begins at the weekend, but said it had approved the “designation of specific places” in Gaza. “This has been presented to the security cabinet and has received the support of the relevant professionals,” the statement said. The terse statement may well have been deliberately vague. Far-right elements of the coalition are adamantly opposed to any form of truce or relief for Gaza’s Palestinian population, but aid agencies have made it clear that the polio outbreak, the first in Gaza for 25 years, would almost certainly spread to Israel if not contained immediately. The Israeli media report said that a pause in operations was demanded by the US secretary of state, Antony Blinken, when he visited Israel last week. The first of two rounds of vaccinations is due to begin on Saturday in an urgent effort to control the spread of the virus after it was found in a baby with paralysis in one leg earlier this month. More than 25,000 vials of vaccine, enough for more than 1m doses, have arrived in Gaza along with the equipment needed to keep them cool while they are being transported. But health experts have warned that it would be virtually impossible to carry out the vaccination drive successfully under bombardment. To stop the spread of the disease, aid agencies must reach 90% of the estimated 640,000 children under the age of 10 in Gaza. That is already challenging as Palestinians have been subjected to an increasing number of evacuation orders by the Israeli military, crowding them into ever tighter, more remote spaces. One possibility suggested by Netanyahu’s statement is that Israeli bombardment would be stopped in different areas of Gaza sequentially, to allow aid workers with the vaccines to move from one area to another. The uncertainty over humanitarian pauses and evacuation orders made planning extremely difficult, said Juliette Touma, a spokesperson for the UN relief agency Unrwa. “Plans are the bread and butter of any successful humanitarian operation. You have got to know how many people you are going to reach: where are they located? How are you going to reach them?” Touma said. “Planning is such an important element of the success of any operation, but in Gaza planning is almost nonexistent.”