The second round of a vaccination campaign to protect 640,000 children in Gaza against polio will also deliver micronutrients - essential vitamins and minerals - and conduct nutritional screening, a senior U.N. Children's Fund official said.

Discussions are also underway about the feasibility of adding further vaccinations to the campaign, including a measles immunization, said Ted Chaiban, UNICEF's deputy executive director for humanitarian action and supply operations.

"There are over 44,000 children born in the last year and who haven't received their basic immunization," he said on Thursday.

The first round of the polio vaccination campaign, which began on Sept. 1, reached its target of 90% of children under 10 years of age, the head of the United Nations Palestinian refugee agency (UNRWA) said on Monday.

It was carried out in phases over two weeks during humanitarian pauses in the fighting between Israel and Palestinian militants Hamas. A second round of the polio vaccinations has to be carried out within four weeks.

The World Health Organisation (WHO) confirmed last month that a baby was partially paralysed by the type 2 polio virus, the first such case in the territory in 25 years.

A high risk of famine persists across Gaza as long as the war continues and humanitarian access is restricted, according to an assessment by a global hunger monitor published in June.

"In the same way that we've been able to reach all children with polio vaccines, we need to move and use the same modality to reach children with their basic vaccines, with some of the nutrition and hygiene interventions that are essential to save their lives," Chaiban told reporters after visiting Gaza, the West Bank and Israel.

"Those are lifesaving interventions and the parties have shown that they can line up when necessary. It needs to happen again," he said.