As a presidential candidate last summer, Donald Trump promised to lead an aggressive fight against the spread of the Zika virus. He urged Congress to fund a proposed $1 billion-plus Zika response plan.
But now, the public health community is expressing strong concerns about President Trump's commitment to maintaining and strengthening the country's infectious disease prevention infrastructure.
Many credit Trump's draft budget, released last month, for proposing the creation of a new federal emergency fund designed to rapidly respond to public health crises. That's something public health leaders have advocated for years.
Creating such a fund would end the need to call on Congress to provide crisis funding when an infectious disease outbreak occurs, as happened with Ebola and then Zika.
"There could be events quite frankly where (having an established emergency fund) could be the difference between a successful response and a failed response," said James Blumenstock, chief program officer for Health Security for the Association of State and Territorial Health Officials.
Yet the Trump budget lacks details on how much money the administration would appropriate for the proposed emergency fund, or how the president wants to pay for it.
If Trump dedicates new funding, then it has the potential to be a powerful tool to aid prevention and response effort in emergencies, experts say. But if funding comes from cutting other public health programs, they say its potential impact would be greatly reduced.
"Any significant reduction in any program that (the Centers for Disease Control and Prevention) administers will have a cascading effect on state and local health departments and would result in a reduction in prevention activities in the communities," Blumenstock said.
Establishing an emergency fund would not be enough to assuage larger concerns among public health experts over Trump's move to repeal and replace the Affordable Care Act and impose other domestic spending cuts that could undermine prevention and response efforts.
Included in the president's draft budget was a proposal to cut the National Institutes of Health by $5.8 billion. The NIH has been the leading funding source for vaccine research and development for several infectious diseases that have had outbreaks in recent years, including Ebola and Zika.
"If you defund the scientific infrastructure in general, all aspects are going to have to suffer and that includes preparedness for new diseases as well as research and therapy for existing diseases," said Dr. David Freedman, professor of medicine and epidemiology at the University of Alabama at Birmingham.
Trump's skepticism about the human-caused sources of climate change is reflected in his proposed 31% cut to the Environmental Protections Agency's budget, which would force layoffs of an estimated one-fifth of the agency's workforce. Climate change have been linked to an increased risk of infectious diseases.
Extreme weather events coupled with milder winters as global temperatures rise have created environments that are breeding ground for diseases, including mosquito-borne infections, that traditionally have spread only in the tropics but now are found in the U.S.
"It's been one of the warmest winters on record, and that's good for the Aedes Aegypti (mosquito) but not good for us," said Dr. Peter Hotez, dean of Baylor College of Medicine's National School of Tropical Medicine. "I'm quite worried that all of that means that it's going to be a pretty bad Aedes Aegypti season this spring and into the summer, and that means there's a pretty high risk for a Zika virus transmission."
Even seemingly unrelated Trump policy decisions could have large public health ramifications. A repeal of the Affordable Care Act would not only mean a loss of health coverage for millions but also would eliminate the CDC's Prevention and Public Health Fund. Created under ACA, the fund provides more than $930 million for CDC programs, accounting for 12% of the agency's total annual budget.
A loss of the that funding would mean slashing $40 million from the CDC's Epidemiology and Laboratory Capacity for Infectious Disease Cooperative Agreement program (ELC), which provides funding to public health laboratories around the country to quickly respond to emerging infectious disease threats.
The ELC program receives around half of its annual funding through the ACA's Prevention and Public Health Fund. Program funds played a crucial role in helping state laboratories rapidly test suspected Zika samples months before Congress approved emergency federal funding last year.
Repealing the ACA and the prevention fund would eliminate ELC's nimble ability to address public health concerns like Zika before lawmakers can react, said Peter Kyriacopoulos, senior director of public policy at the Association of Public Health Laboratories.
Erasing the prevention fund also would be a big blow to the CDC's immunization program, which receives more than $324 million for states to improve their immunization infrastructure and increase vaccine coverage among children.
It's questionable whether Trump's proposed budget would have an immediate impact on the response effort to the spread of Zika this season. Many state and local public health departments already have received at least a portion of the $1.1 billion in emergency Zika funding approved by Congress last year.
But the question remains how the Trump budget cuts would affect the nation's response efforts once that money is used up, when a new disease threat could emerge. There is worry that if health departments were faced with an outbreak of Zika plus a sudden epidemic of measles or influenza, it could push some agencies beyond their limits.
"So far we have been extraordinarily lucky in this country to have sequential public health emergencies instead of simultaneous emergencies," Kyriacopoulos said.
Freedman said a larger concern lies in the potential impact Trump's budget cuts could have on efforts to recruit the next generation of scientists and researchers. "The best and the brightest aren't going to pursue a career in science if there are no opportunities for either jobs or funding," he said.