Don't epidemics usually create sick people? I realize the counter-argument will of course be "we don't know the long-term effects," but people have been exposed

Don't epidemics usually create sick people? I realize the counter-argument will of course be "we don't know the long-term effects," but people have been exposed to aerosolized glycerine/propylene glycol for decades in the form of fog machines at concerts and clubs. Surely if this was the next asbestos we'd be seeing something by now.