Mirsal Adel, 47, had never struggled to find vaccines for his children. In his hometown of Ibb, in southwestern Yemen, public hospitals and paediatric clinics always provided them free of charge.

But when it came to vaccinating his fifth child, a four-month-old boy, securing a shot was far from straightforward.

“I visited the hospital more than once, and I was told that UNICEF, which used to provide the vaccines, stopped supplying them, with no word on when they might arrive,” said Adel.

In October 2025, the United Nations children’s agency, UNICEF, halted operations in areas controlled by the Houthis following the detention of dozens of UN staff members – including UNICEF workers – and raids on its premises. The Houthis have been fighting Yemen’s internationally recognised government for years, and have periodically cracked down on aid sector workers.

The Health Ministry in Yemen’s Houthi-held capital, Sanaa, confirmed to Al Jazeera that the final vaccine shipment it received arrived on September 4, 2025. In late July 2026, the government’s Health Ministry in Aden warned that nearly five million children in Houthi-controlled areas had been cut off from essential routine immunisations.

One of them was Adel’s newborn.

“Our children’s health is a red line, and we must do everything we can to get them vaccinated,” said Adel, who decided last week to travel with his son to Taiz, a government-held city some 75km (47 miles) away, where vaccines are still available.

He said the trip cost him about $100, a prohibitive expense for many families in impoverished Yemen.

“Vaccination teams used to go door-to-door to vaccinate children, but this year everything changed suddenly, and getting a reliable vaccine now costs a lot,” said Adel, who works as a treasurer at a local company. “Today, not everyone can afford the travel expenses to get their children vaccinated.”

Although he is relieved to have secured the two initial doses of polio and pneumococcal vaccinations, he is already anxious about any upcoming trips. “I hope children’s vaccines will be available locally next time so I won’t have to resort to travelling again,” he said.

Halting UNICEF operations

The war in Yemen broke out in late 2014, when the Houthis seized much of northern and western Yemen, including Sanaa, prompting a Saudi-led coalition of Arab countries to intervene in support of the internationally recognised government in March 2015. A United Nations-brokered ceasefire in 2022 significantly reduced fighting, but tensions have escalated since July, with fighting growing fiercer in recent days.

In March this year, the United Nations Office for the Coordination of Humanitarian Affairs said that only 59.3 percent of Yemen’s health facilities remained fully functional, while overall complete vaccination coverage stood at 63 percent.

The figures, however, reflect the conditions before the total exhaustion of vaccine supplies in Houthi-controlled areas by July, meaning current national coverage rates are likely significantly worse.

Anees al-Asbahi, spokesperson for the Health Ministry in Sanaa, blamed UNICEF and Gavi, the Vaccine Alliance, for the collapse of the vaccine supply. He said authorities had informed both agencies early on regarding the impending shortages, yet no action was taken before all nine routine childhood vaccines were entirely exhausted.

“The primary reason for the disappearance of childhood vaccines is the politicisation of humanitarian work,” he said, repeating an accusation made by the Houthis against UN agencies, particularly following last year’s decision to relocate their operations to Aden.

“Since UNICEF halted its operations in Sanaa for political reasons, they stopped supplying us with vaccines,” he added. “Furthermore, because we live under a blockade by Saudi Arabia, we cannot import them ourselves.”

When contacted by Al Jazeera, UNICEF Yemen declined to comment on the allegations, saying only that it is doing its best to help every child access vaccines. Al Jazeera also contacted Gavi for comment, but received no response.

Meanwhile, the UN continues to demand the immediate release of dozens of its personnel, alongside staff from international and local humanitarian organisations currently detained by the Houthis. The UN has also called for the return of assets seized during raids on its offices, and the lifting of operational restrictions on aid groups and their personnel.

‘It breaks my heart’

The Health Ministry in Aden said in late July that it had sufficient vaccines for the entire country, including Houthi-controlled areas. However, it accused the Houthis of creating obstacles that prevent the receipt and transport of these supplies from government-controlled areas.

“Vaccines designated for all governorates of the Republic, including those under Houthi control, are available through health sector partners in accordance with approved international supply mechanisms,” it said. “However, the ongoing restrictions and obstacles imposed by the Houthis – which hinder their receipt, transportation and distribution according to technical standards – have prevented them from reaching the targeted children.”

Ali al-Waleedi, the deputy health minister in Aden, said the ministry had planned to carry out two polio vaccination rounds this year but accused the Houthis of not cooperating.

“The Houthis refused to accept vaccines designated for areas under their control and have shown no willingness to resolve the crisis,” al-Waleedi told Al Jazeera. “They rejected the vaccines, even though it had been agreed to allocate more than 65 percent of the total supply to areas under their control.”

Responding to the allegations regarding the rejection of shipments, al-Asbahi said there has been “no coordination” with the ministry in Aden. “We cannot accept shipments arriving by road, as they could be spoiled. UNICEF and Gavi are responsible for this, and they must uphold their responsibility to provide our children with vaccines.”

While the two health ministries present different accounts, parents such as Mohammed Abdulwahed wait for the rival authorities to reach an agreement and restore access to paediatric vaccines.

“There was a shortage of vaccines earlier this year, and we used to struggle to get them, but now we cannot find them at all in Sanaa,” said Abdulwahed. “I know some families are travelling to government-controlled areas, but that costs a lot, and I simply can’t afford it.”

Thikra, a healthcare worker who has served on door-to-door vaccination teams and currently works at a vaccination clinic in a Taiz hospital, said that dozens of children from Houthi-controlled areas were arriving at the facility each day to be vaccinated.

“It breaks my heart to see children deprived of essential vaccines while authorities in Sanaa and Aden exchange blame,” she said.

“Political issues should be kept completely separate from children’s health, and both ministries must find a solution so all children can access free vaccines,” she said, stressing that immunisation is a basic right for every child.

“I urge the international community to step in, as the next generation could suffer severe health consequences if an urgent solution is not found to restore vaccine supplies.”