Chloroquinine is a synthetic version of quinine. I see some evidence that for malaria, the chloro version may be more effective, but both have an impact. I have no idea how that ties to corvid-19. In any case, I have been buying tonic water (probably 75-80 mg quinine per liter). I just drink it plain or an occasional gin (Sapphire) and tonic. Hey it cannot hurt, and it may have a prophylactic effect.
It worked for the Brits in tropical zones; though concentration of quinine was much higher in their tonic water.