[Broken_Hippo]

I'm not on O, but on another drug for MS (fingolimod), and can almost promise they aren't getting vaccinated twice a year.

First, some of the vaccines are simply dangerous as some are live vaccines. I cannot take some travel vaccines because of this: The risk of me simply catching the disease is too great. Same for their drug.

Second, there is some concern about the effectiveness of the vaccines. For example, the covid vaccine: I wound up with an extra booster because they weren't sure how well I was protected. And this can be the case with other vaccines: You might not get the same sort of protection out of it.

The outcome is generally that it isn't worth it to revaccinate folks. And for myself: It isn't that I'm unprotected completely. My immune system is just... hampered. I think the infusions cause more of an issue, but again, isn't worth the revaccination.