This question, though very worthwhile, doesn't necessarily need to be answered. Vaccines for EBV are under development. If we stop most EBV infections, we can stop most MS.
Something like CRISPR/Cas9 editing may be the way to treat persistent EBV and other herpesvirus infections.
With little protein expression, training T-cells to identify viral MHC-epitopes is unlikely to ever clear something like EBV. There's no proteins, there's no virions, there's no proteases, the better target is the genome itself: