Immunotherapies influence the influenza vaccination response in multiple sclerosis patients: an explorative study

The immunogenicity of influenza vaccines in MS patients undergoing immunomodulatory treatment is not well studied.

This explorative study investigated the influence of immunomodulatory treatment on MS patients receiving pandemic H1N1 (swine flu) vaccination in 2009 and seasonal influenza vaccination in 2010.

We investigated the immune response to pandemic H1N1 vaccination among 113 MS patients and 216 controls during the pandemic of 2009. We also investigated the serological response to seasonal influenza vaccination (2010 - 2011 season) among 49 vaccinated and 62 non-vaccinated MS patients, versus 73 controls. We evaluated these vaccine responses by haemagglutination inhibition assay.

MS patients receiving immunomodulatory treatment had reduced protection (27.4%), compared to controls (43.5%) (p = 0.006), after pandemic H1N1 vaccination (2009). The rates of protection were not influenced by interferon beta treatment (44.4% protected), but were reduced among patients receiving glatiramer acetate (21.6%), natalizumab (23.5%), and mitoxantrone (0.0%). A similar pattern emerged after MS patients received a seasonal influenza vaccination in 2010.

These findings suggest that MS patients receiving immunomodulatory therapies other than interferon beta should be considered for a vaccine response analysis and perhaps be offered a second dose of the vaccine, in cases of insufficient protection.