It’s the malaria drug everyone from President Trump to Elon Musk is hoping can help make a difference in the fight against coronavirus. The problem? There’s just not enough data yet to say for certain whether hydroxychloroquine is effective against COVID-19.

Fortunately, researchers at the University of Minnesota have just launched what could be one of the biggest human trials to see whether or not hydroxychloroquine can help prevent healthcare workers and others exposed to the virus from getting sick.