It's not an antibiotic, it is an anti-malarial, and has been used as a malarial prophylaxis safely since 1955.
Ask any Vietnam vet.
Quinine was Widely used in SW Pacific during WWII as a prophylactic against malaria. Inasmuch as that is a disease not a virus I wonder how it quells this blasted nuisance. In any event, I intend to quaff a few gin and tonics over the next few weeks. Got to be careful to use the diet variety or these drinks will turn me into a balloon.