Sept. 24 (UPI) -- President Donald Trump is again clashing with top U.S. health officials over a COVID-19 vaccine, this time over plans to tighten study requirements to better ensure a vaccine is safe and effective.
During a news conference Wednesday, Trump indicated that the White House could overrule the FDA on the issue.
"That has to be approved by the White House," he said. "We may or may not approve it."
Trump said the FDA plan to tighten guidance "sounds like a political move."
While the White House has no regulatory authority over the FDA, officials say agency guidelines usually do go through a review process by the White House budget office.
A number of potential vaccines are now in development in labs worldwide, including U.S. companies Moderna, Pfizer and Johnson & Johnson.
Wednesday isn't the first time Trump has clashed with administration health officials. Last week, he contradicted Centers for Disease Control and Prevention Director Dr. Robert Redfield over the expected timeline for a vaccine.
Dr. Anthony Fauci, the nation's top infectious diseases expert, said earlier this week disagreement from federal leaders is one of multiple factors hindering the fight against COVID-19 in the United States.
Updated data from Johns Hopkins University on Thursday showed 37,300 new cases and 1,100 additional deaths nationwide on Wednesday.
The death count was the highest for a single day in more than a week. Since the start of the outbreak, there have been 6.94 million cases and 201,900 deaths in the United States, according to Johns Hopkins.
Redfield told a Senate committee on Wednesday that the vast majority Americans remain susceptible to infection -- noting that more than 90% have yet to be exposed to the coronavirus.
Preliminary studies, he added, show the national spread has so far been uneven. In some states, a fifth of the population has been exposed while that share is just 1% in others.
Data from Johns Hopkins indicates that about 2% of the U.S. population has been infected.
Advocates of a "herd immunity" strategy, like White House medical adviser Dr. Scott Atlas, favor allowing an unchecked spread of the virus to build immunity. Experts say as much as 80% of the population would need to be exposed to achieve this goal.
Others, including Fauci, say that approach would result in an "unacceptable" number of deaths.
The national death toll could surpass 600,000 by January under the strategy, some researchers have said.
In Wisconsin, officials at the University of Wisconsin in Madison said in-person classes will resume gradually this weekend -- despite a new outbreak among students.
Chancellor Rebecca Blank said some courses will resume Saturday and the rest will be left up to departments and instructors.
The university closed campus facilities and moved all classes online earlier this month, just one week after they resumed.
"No one wanted our semester to start this way, but it has underscored that strict adherence to public health protocols is essential," Blank said.
Gov. Tony Evers declared a new public health emergency on Tuesday and extended a statewide mask mandate through late November. He said Wisconsin is seeing an "unprecedented, near-exponential growth" of the virus.