• New WHO analysis of 31 studies over 15 years reaffirms there is no link between vaccines and autism, says WHO chief
• Tedros says new US bilateral MOUs 'do not replace' multilateral cooperation, cannot substitute for global platforms involving 194 states

GENEVA

The World Health Organization warned on Thursday that disease outbreaks in Gaza may be spreading largely undetected due to the near-total collapse of surveillance and laboratory systems.

Teresa Zakaria, WHO's unit head for humanitarian and disaster action, said the living conditions in the enclave are so severe that "we can't even describe it anymore," adding that "all the basis for diseases to develop in a constricted environment with very limited access to prevention, to detection and response are all indicating that outbreaks can really spread out of control and very rapidly."

Her remarks came during an Association of Accredited Correspondents at the United Nations (ACANU) media briefing in Geneva.

Zakaria said humanitarian access and diagnostic capacities remain "very limited," making early detection and response nearly impossible.

"What is very important here to highlight is that we are probably missing the vast majority of diseases that are spreading in the territory at the moment just because we have not been able to detect them," she said.

WHO cannot quantify how many outbreaks are occurring or their intensity because "labs aren't present to actually allow us… to detect them, the various pathogens that are circulating."

She reiterated calls for "unhindered access for humanitarian supplies… to revive the health system and be able to detect these diseases."

No link between vaccines and autism

WHO Director-General Tedros Adhanom Ghebreyesus, addressing the briefing, announced new findings from the Global Advisory Committee on Vaccine Safety, which reviewed 31 studies over 15 years.

He said the committee found "no causal link between vaccines and autism," including vaccines containing aluminium or thiomersal.

Tedros said: "This is the fourth such review… all reached the same conclusion: vaccines do not cause autism."

Vaccines remain "among the most powerful, transformative inventions in the history of humankind," he added, noting that while WHO monitors side effects, "autism is not a side effect of vaccines."

Funding crisis, restructuring and staff cuts

Tedros said the pressures facing the global health system this year have been unusually severe.

"As you know, 2025 has also been a year of significant challenges for global health and for WHO," he said, pointing to "steep cuts in development assistance" that have "caused severe disruptions to health services in many countries."

He warned that "early estimates are indicating that childhood mortality could increase for the first time this century."

Tedros added that steep cuts in development assistance and the US withdrawal from WHO left the agency facing "a salary gap… of about $ 500 million" for the next two years.

Patrick Nicollier, WHO's chief human resources officer, said the organization tried to shield staff from the impact as much as possible. "We have tried to preserve the organization from cuts as much as possible, and the transformation initiatives that have been launched in 2017 have helped us to prevent a number of staff cuts," he said.

Nicollier added: "We had about 1100 staff members who left through natural attrition or… a voluntary early retirement package. Unfortunately, this was not enough… and that led us to go through the restructuring and to cut an additional 1280 positions."

Tedros said WHO's dependence on a small group of donors had long put the agency at risk, making member states' recent decision to increase assessed contributions to 50% of the core budget by 2031 "very historic."

Technical cooperation with US institutions continues, he said, despite political uncertainty. Tedros warned that US withdrawal would be "a lose-lose," stressing: "There is no good reason for the US to withdraw from WHO."

Addressing questions about memorandum of understanding (MOUs) being signed between the US and several developing countries, Tedros said such agreements did not undermine WHO's role.

"This is an agreement between two adults and between two sovereign nations, and I know those countries will come to the table with their national interests, and I don't think this is wrong," he said, adding that bilateral arrangements were common.

He stressed that these MOUs do not weaken global mechanisms. "It doesn't affect and I'm not worried… Still, it cannot replace an agreement of an international nature that brings 194 countries," he said.

Tedros noted that WHO's multilateral platforms remain indispensable because "you never know where the next outbreak will come," and emphasized that bilateral and multilateral cooperation can coexist. "They can have bilateral agreements and they can still use the platform… I'm not worried, because we will still need the common platform that brings almost everybody to the table."

Sudan crisis worsening

Tedros also warned of a severe deterioration in Sudan, saying the situation in the country "is very desperate" and "it's not getting the right attention from the international community."

More than 14 million people have been displaced, and diseases such as malaria, dengue and cholera are surging, he noted and said: "Even the number of deaths due to cholera is the largest now in the world."

Tedros urged the international community “to give the right attention to Sudan and address this tragic situation.”