Responses of solid organ transplant recipients to the AS03-adjuvanted pandemic influenza vaccine

Solid organ transplant (SOT) recipients are a priority group for influenza vaccination and strategies enhancing immunogenicity are needed. We determined adverse reactions, changes in biomarkers of graft function and immune responses to two doses of the AS03-adjuvanted influenza A/09/H1N1 vaccine in 216 SOT recipients and in 138 controls after one dose. Antibody responses were measured by haemagglutination inhibition and confirmed by microneutralization. We calculated geometric mean titres (GMT) and seroprotection rates (GMT≥40). Adverse reactions were fewer than in controls and graft function remained unaffected. Seroprotection was achieved by only 70.3% of SOT recipients, with significant differences between groups (lung 43.6%, heart 72.0%, kidney 83.3%, liver 83.3% and pancreas 85%), compared to 87% of controls (P