Early blight prevention with copper fungicide

[wildcat62]

I'm new to the use of copper fungicide. So this may be a stupid question. It looks like this stuff prevents the blight but will it kill/suppress it if it is already present. I recently noticed what I believe to be early blight & after discussion with the local coop I pulled all foliage that appeared to be diseased & anything that came close to contacting the ground. Sprayed the copper from top to bottom heavily. We got another rain about 24 hours after the application. I go out this morning and looks like a few more leaves are affected. I realize I'll have to spray again today after the sun goes down as it's sunny hot/humid already this morning. Will the copper kill the spores are will it only prevent new foliage from succumbing? What a battle.... I'm not giving up.... The plants do have a heavy fruit set & I can't wait to bite into them. Any advice would be greatly appreciated???