I didn’t notice until your comment and it’s too late to edit now, but the first place I wrote “vaccine” should have been “virus”, see also my response to myself

I didn’t notice until your comment and it’s too late to edit now, but the first place I wrote “vaccine” should have been “virus”, see also my response to myself. (Revaccinatiom may be needed after rituximab, which was specifically designed to attack immune memory cells in case if autoimmune disease - which apparently measles does as well - but the MMR vaccine doesn’t do that. I just typeda wrong word and didn’t notice)