There is no cure, and the symptoms don't show up in all of the plants that have the disease, or they might show up only after a number of years. The main thing, though, is that it's literally nothing to worry about. I have at least 200 roses in my garden that occasionally exhibit RMV symptoms, usually in spring. Some of them are 30 years old and they all perform as well as my other roses. All three of my Blaze roses have exhibited the symptoms at one time or another.
It's a very common and mostly harmless rose disease. I realize that the sight of a few marred leaves can be upsetting to some gardeners, but I personally like variegated foliage, so it doesn't upset me at all.
I once read that there isn't a single Rose de Rescht in the United States without RMV. It was in all of the grafted Rose de Rescht bushes for so long that even the own-root ones would have it now because they would have had to originate as cuttings from an infected rose.