"To the scientists in our midst. Will this work?"
Too early to tell. There is scant data right now to support its efficacy. That's why a solid, well controlled clinical trial needs to be done. See links below highlighting the holes in the current data.
https://twitter.com/GaetanBurgio/status/1241201751916568576
https://blogs.sciencemag.org/pipeline/archives/2020/03/20/chloroquine-past-and-present
https://www.statnews.com/2020/03/22/why-trump-at-odds-with-medical-experts-over-malaria-drugs-against-covid-19/
Trump doesn't understand science. Do not get your scientific/medical advice from Trump. His poor understanding, horrible advice and terrible messaging have already led to people dying.
https://www.cnn.com/2020/03/23/health/arizona-coronavirus-chloroquine-death/index.html
As Cityslicker just wrote "The man to listen to is Dr Fauci, and as he has said, there has not yet been a controlled clinical trial. So while it looks promising, nobody yet knows if it helps."
BDAZ