RE: Is the goal to prevent exposure/infection, or to prevent illness?
Seeing how Doctors and Healthcare workers are using HCQ for themselves, I would say their primary goal is to prevent infection.
Why? Because one can be infected and still be asymptomatic and that is DANGEROUS in a hospital setting with so many vulnerable people.
So, if it does not prevent infection, taking it is pretty useless and I would suggest saving it for AFTER you are infected.
If the viral load is small enough, the probability of viral shedding is commensurately small. Person to person transmission is the exchange of shedded virii.
In a medical setting, proper use of PPE can contain a small amount of shedding. Otherwise, PPE would be useless against any patient’s infection.
Think of the tetanus shot. It is given after a person is potentially exposed (such as stepping on a rusty nail), but acts as prophylaxis against the disease for about 10 years after. It doesn’t prevent introduction of the infection (darned nails), but prevents the exposure from becoming illness.
In the case of the CCP virus, prophylaxis is not intended to prevent exposure, nor does it prevent small scale infection. It prevents progression of the infection to the point where the carrier sheds significant amounts of virus, and where the carrier experiences significant effects of the resultant illness.
If HCQ and zinc can prevent replication at a 90% effectiveness rate (or higher), it is effective at preventing the disease caused by the CCP virus, and is likely somewhat effective in preventing person to person transmission by lowering the amount of virii in the carrier’s system so that there is much less viral load to shed.
Needless to say, I disagree with your conclusion, but I greatly appreciate the reasonable discussion over how our separate conclusions were arrived at.