Vaccine Trials

I’ve recently applied for the GSK vaccine trial in Richmond Virginia and got a email back saying “We aren’t doing trials in your country ?” I live in the US ? They just haven’t started yet ? Also with these vaccines is it like 2 shots ? And you could possibly be “cured” or non transmittable or when they say phases it’s 3 shots over like 3 years and even then that could possibly fail ?