Two Doses of Inactivated Influenza Vaccine Improve Immune Response in Solid Organ Transplant Recipients: Results of TRANSGRIPE 1-2, a Randomized Controlled Clinical Trial.
Cordero E, Roca-Oporto C, et al.Clinical Infectious Diseases 2017; 64(7): 829-838.
Aims
To determine if the efficacy and immunogenicity of the seasonal inactivated trivalent influenza vaccination can be increased among solid organ transplant recipients (SOTR) with a second dose, 5 weeks after the standard influenza vaccine.
Interventions
Patients were randomly assigned to receive either the standard intramuscular single-dose vaccination (control group), or a second dose of the same influenza vaccine 5 weeks apart (booster group).
Participants
499 SOTR (liver, kidney, heart or lung) aged ≥16 years who were recruited at least 30 days after transplantation.
Outcomes
The primary outcome measured was seroconversion. Secondary outcomes included immunological response, such as seroprotection rate and postvaccine geometric mean titer.
Follow-up
12 months
CET Conclusions
This open-label trial investigated the efficacy of one versus two doses (with a booster) of influenza vaccine in solid organ transplant recipients. Use of a booster dose improved seroconversion rates in the per-protocol analysis, but did not achieve significance in the multivariate modified intent-to-treat analysis. Rates of seroprotection were improved in both the mITT and per protocol analysis. However, no difference in seroprotection or seroconversion were seen at 1 year post-vaccination. Safety profiles of both strategies were similar. These results suggest that in solid-organ transplant recipients, a booster dose of influenza vaccine offers increased effectiveness without compromising safety. Annual vaccination is required regardless of strategy used.
Data analysis
Modified intention-to-treat analysis
Trial registration
EudraCT - 2011-003243-21