Although President Trump claimed that convalescent plasma is his latest miracle cure for coronavirus, medical experts around the world say that while the treatment holds promise, its effectiveness still needs to be clinically proven, the Washington Post reports.

Just last week, the CDC announced that the effectiveness of convalescent was still being tested, and an emergency authorization for use as a coronavirus treatment was put on hold.  Now, some US researchers and the World Health Organization has echoed those concerns.

I’m quoted in this ⁦@djusatoday⁩ piece. Convalescent plasma may have some efficacy, but we need to have definitive data and tonight’s EUA was clearly a political stunt. https://t.co/53AXNfStrU

— Jonathan Reiner (@JReinerMD) August 24, 2020

“The urgency of the crisis has elided with a false sense we should skip over rigorous studies of interventions because we don’t have enough time,” Peter Bach, director of Memorial Sloan Kettering’s Center for Health Policy and Outcomes, told The Washington Post.

The WHO noted that while there are a number of tests going on around the world, the tests that have completed are providing only preliminary results.

“There are a number of clinical trials going on around the world looking at convalescent plasma compared to the standard of care. Only a few of them have actually reported interim results… and at the moment, it’s still very low-quality evidence,” WHO chief scientist Soumya Swaminathan told a news conference, reported by the BBC.