Cell-Mediated Immune Responses after Influenza Vaccination of Solid Organ Transplant Recipients: a Secondary Outcomes Analysis of a Randomized Controlled Trial.L'Huillier, A. G., et al. (2019).
Journal of Infectious Diseases [record in progress].
This study aimed to compare the CD4+ and CD8+ T-cell responses of the high-dose (HD) and the standard-dose (SD) trivalent inactivated vaccine in solid organ transplant recipients.
This is a substudy of the CMI study. Patients were randomized 1:1 to receive either HD vaccine containing 60 µg of antigen per strain or SD vaccine containing 15 µg of antigen per strain.
60 patients from the CMI substudy (30 high dose vaccine vs 30 standard dose vaccine).
The main outcome being assessed was the proportion of influenza-specific polyfunctional T cells elicited by vaccine antigens. Seroconversion was defined as a ≥4-fold increase in antibody titers compared with prevaccination as well as reaching a seroprotective titer.
This manuscript reports a study on a subset of patients from a randomized trial of high versus low-dose influenza vaccine in solid organ transplant recipients. The authors demonstrate a significantly higher cellular immune response in the high dose group. The finding is interesting as it has been suggested that cell-mediated immunity is important in protection against influenza in immunosuppressed patients. There are some limitations – it is not clear whether the response in either group is clinically protective or sustained, and the patients included in this substudy represent a small self-selected cohort from the overall study.
ClinicalTrials.gov - NCT03139565