No. Nothing will cure Marek's, unfortunately. You can give antibiotics for support as well as vitamins that help the immune and nerve systems in the body, but that's about it I'm afraid. Another thing I personally use is FloraGen 3. It is a human probiotic and it has billions of the live cultures of 3 different probiotics in one capsule. Immunity starts in the guts. Human, animal, doesn't matter. My thoughts are this, no it isn't going to get rid of Marek's, way too late for that...but what it can do is keep things working right so a secondary infection or disease doesn't step in and finish off the poor bird. I've had many a poor bird die from the secondary things.