Humoral immune response to influenza vaccine in natalizumab-treated MS patients

Objectives: Natalizumab is a drug with documented efficacy in relapsing-remitting multiple sclerosis (RRMS). The mechanism of action of natalizumab has immunosuppressive properties and it is not yet investigated if treatment with natalizumab affects the immunological response to vaccination. This study aims to investigate the humoral immune response to influenza vaccine while undergoing treatment with natalizumab. Methods: A cohort of 17 RRMS patients treated with natalizumab and 10 healthy controls received trivalent influenza A/B vaccine. Influenza-specific immunoglobulin G (IgG) levels were determined at baseline and after 4, 8, and 12 weeks. Results: Both groups experienced a significant increase in anti-influenza B IgG after the vaccination. Both groups also experienced a smaller increase in anti-influenza A IgG, but this was only significant for the natalizumab group. The IgG titers compared between the groups did not differ significantly at any of the time points. Discussion: These results indicate that vaccination against influenza in patients treated with natalizumab yields a humoral immune response comparable to that achieved in healthy individuals.