Matthew Herder and colleagues warn that these policies pose a grave threat to global health, risking multiple, international infectious disease outbreaks and potentially leading to millions of deaths and infections, particularly in low and middle income countries.
Key US actions detrimental to global health include withdrawing from the World Health Organization (WHO), reducing funding to combat diseases like HIV/AIDS, malaria, and tuberculosis in many of the world's poorest nations, altering the US childhood vaccination schedule, and reducing commitment to pandemic preparedness.
The authors note that while a PHEIC has never been declared due to the political actions of a single country, the overriding consideration is risk.
And given that the recent US decisions have greatly amplified the risk of international disease spread, they argue this meets the criteria for a PHEIC under International Health Regulations (IHRs). The IHRs define a PHEIC as an "extraordinary event" that creates a "public health risk to other states through the international spread of disease."
Declaring a PHEIC can also mobilise funding and encourage the use of compulsory licensing of essential medicines to mitigate the harms stemming from US actions, they add.
Although they acknowledge that a PHEIC declaration could prompt further US backlash, the authors stress that hundreds of thousands of people have already died due to US actions since President Trump assumed office in early 2025, with more expected. As such, they say the international community, led by the WHO, must work collectively to protect global health.
"Whether or not WHO determines that the US's actions amount to a PHEIC, we should not wait to call the US president and his administration for what it is—the worst public health emergency in the world—and act accordingly," they conclude.
A related feature describes how new US foreign aid rules create a "deadly triple tripwire" for recipient organisations by expanding existing abortion-related restrictions and banning funding for gender and diversity programs.
Sara Casey, an associate professor at the Columbia University Mailman School of Public Health, warns that the repercussions will be severe. "We're going to see facilities shut or lose staff or services, which means we're going to see things like maternal mortality and unsafe abortions increase," she says.
