President Donald Trump signed an executive order on his first day back in office to withdraw the United States from the World Health Organization, reigniting concerns about future pandemic response.

The move follows Trump’s previous attempt to leave the WHO in 2020, a decision reversed by President Joe Biden upon taking office. The WHO, which provides global health guidance, played a key role during the COVID-19 pandemic, issuing recommendations on masks, mass gatherings, and quarantines.

Without WHO membership, experts say the U.S. may face challenges in coordinating responses to future health crises. Schools, in particular, could see extended shutdowns if another pandemic emerges.

“I would imagine so, or I would imagine we would have a lot more deaths,” said Sara Jongsma, a human services teacher, when asked if another pandemic could lead to months of online learning.

The U.S. was the largest contributor to the WHO, providing over $1 billion in funding. That money supported global disease detection, outbreak response, and vaccine distribution.

It remains unclear how the U.S. will replace the WHO’s guidance in a future public health emergency.