My cure for the common cold/flu is Sudafed and weed. For all other ailments, replace the Sudafed with whatever other drugs make you feel better.
I do think that smoking weed will make your immune system slightly weaker, so it may take longer to get over a cold, but you wont feel as shitty while you have the cold. I've never been able to tell though. My colds usually hang for weeks anyway though.
I give smoking while sick a