There are obviously other causative factors influencing MS. One is EBV, the other is likely a specific type of immune system.
Long answer is that the question is premature (we need to answer more mechanistic questions first, and then we need to have an actual potential vaccine strategy to talk about) and there is currently no particular reason to suspect this.
Are you implying that that a vaccine cannot eliminate EBV?
Additionally, a faulty immune response also means your immune system can't differentiate between EBV and your nerve cells. So theoretically speaking even if there's no EBV in your body having MS means that your body thinks EBV is in your body even if it's not. A vaccine in my mind could still induce this reaction.
Same with the Corona vaccines unlike this implies https://news.ycombinator.com/item?id=29942670
your blog is highly educational. i'm interested in learning more about EBV and other viruses.
for instance, given that VZV is common but not every infection causes shingles, how does VZV pass koch's postulates to establish causality?
similar question applies to SARS-CoV-2 and CRS.