Annual influenza vaccination is recommended for immunocompromised patients.1 2 Rituximab, an anti-CD20 monoclonal antibody, recently approved by American and European authorities for the treatment of rheumatoid arthritis (RA) patients failing tumour necrosis factor (TNF)-blocking agents, diminishes the number of circulating B cells for a period of six to nine months after infusion.3 4 Circulating plasma cells and immunoglobulin levels are not affected by this therapy. Based on data in lymphoma patients, the package insert states that patients should not be vaccinated from one month before the administration of rituximab until six months after.5 6 In those studies the underlying lymphoma and treatment …