Vice President Mike Pence told a news briefing Sunday that hydroxychloroquine will be used in a 3,000-person study at Henry Ford Hospital in Detroit to test the effectiveness of the anti-malarial drug in treating novel coronavirus patients.

Why it matters: President Trump has touted the drug as a potential game-changer, but there's no conclusive proof that it works in COVID-19 cases, per National Institute of Allergy and Infectious Diseases director Anthony Fauci.

The trial will be "the first major, definitive study in healthcare workers and first responders of hydroxychloroquine as a preventative medication," noted study organizer William O'Neill, an interventional cardiologist and researcher with Henry Ford Health System, in a statement.

Zoom in: The study will "look at whether the drug prevents front-line workers from contracting the virus," according to the statement.

Once health care workers and first responders enrolled in the trial provide a blood sample, they'll "receive vials with unidentified, specific pills to take over the next eight weeks," per Henry Ford Health System.

These will consist of a once-a-week dose of hydroxychloroquine, a once-a-day dose or a placebo. Participants won't know which group they're in.

"They will ... be contacted weekly and in person at week 4 and week 8 of the study to see if they are exhibiting any symptoms of COVID-19, including dry cough, fever or breathing issues, as well as any medication side effects. At eight weeks, they will be checked again for symptoms, medication side effects, and have blood drawn. Results will be compared among the three groups to see if the medication had any effect."

— Henry Ford Health System statement

Of note: "The study medication was specially procured for this study [from the Food and Drug Administration] and will not impact the supply of medication for people who already take the medication for other conditions," Henry Ford Health System said.

Our thought bubble, per Axios' Sam Baker: Hydroxychloroquine has shown some promise against the coronavirus in a small French study, but it's not federally approved to treat COVID-19, as no official studies had been conducted to determine whether it's both safe and effective for those sick patients.

Go deeper: Inside the epic White House fight over hydroxychloroquine

Editor's note: This article has been updated with more details on the study.