The Marek disease scenario is more a result of massification of poultry industry and the fact that Marek-infected chickens are infectious for life, rather than the vaccination itself. That's several orders of magnitude higher in terms of mutation lottery tickets.
If you're gonna use the ever-classic Marek scenario to push against vaccination, at least use it against the vaccination of a disease that shares some basic characteristics with MD.
If you're gonna use the ever-classic Marek scenario to push against vaccination, at least use it against the vaccination of a disease that shares some basic characteristics with MD.