MOG and viral infectious disease: We did, indeed, observe lower numbers of unstimulated cells secreting IFN-γ at W52 and W96, but we only observed lower reactivity to MOG and MBP at W96.This may also, at least partly, explain why patients treated with cladribine are at increased risk of certain viral infections which are generally controlled by IFN-γ-dependent type 1 immune responses (49).