Recalculating back the percentages, they have in this study only 2 (!!) out of 147 MS children that are not carrier of the EBV specific antigens.
That is only 2 away from being able to suggest that EBV is to consider as a necessary "pre"condition (= not the same as the cause) for developping MS.
If I was a researcher, those 2 would be the cases I would focus on : is it 100% sure MS, identical symptoms, other subtype, recheck/redo the tests, ....
Someone has read (bought) the compete article ?