I do not. To make a long discussion short, as near as I can calculate it, Mareks prevents 1 to 2% of death from Mareks Cancer. Without the shot, 5% die of it. With the shot, 3% die from it. The inoculation does not stop them from getting Mareks, it only helps prevent the cancer from killing the chicken at 1 to 2 years old.
Most breeders are going for resistance.
Another fact, borne out from research, is that you can have mixed inoculated and not inoculated chickens in your flock. Mareks is like coci it is everywhere.