The physician information about Tysabri shall contain the following key elements: • Restricted indication • Atypical/ opportunistic infections in particular PML including: o Diagnosis of PML including differentiation between PML and MS relapse o PML management algorithm o Possibility of other opportunistic infections • Infusion reactions • Hypersensitivity reactions • Antibody formation • Need to inform patients about the benefits and risk of Tysabri and provide them with a patient alert card.