The benefit of influenza vaccination after bone marrow transplantation.

Influenza vaccine is recommended yearly for recipients after the sixth month of BMT. Although a higher risk of complications of influenza is expected to occur in BMT patients, no study has addressed the clinical efficacy of influenza vaccination in this setting. Focusing on the clinical benefits of influenza vaccination, we evaluated the risk factors for influenza infection in a cohort of 177 BMT recipients followed up for 1 year. Influenza was diagnosed in 39 patients. Multivariate analyses showed that seasonal exposure and more aggressive conditioning regimens were independently associated with increased risk for influenza. Influenza vaccination and steroid use showed a protective role. Of the 43 patients who had received BMT longer than 6 months, 19 were vaccinated (compliance rate = 44.2%) and vaccine efficacy was 80%. We conclude that influenza vaccination plays an important role in protecting BMT recipients against influenza and all efforts should be made to ensure good compliance with vaccination.