The annual influenza vaccine is recommended for solid organ transplant recipients (SOTR) although studies have shown suboptimal immunogenicity. Influenza vaccine containing higher dose antigen may lead to greater immunogenicity in this population.
Method: We conducted a randomized, observer-blind trial comparing the safety and immunogenicity of high dose (HD; FluzoneHD, Sanofi) versus standard dose (SD; Fluviral, GSK) influenza vaccine in adult SOTR. Patients were randomized 1:1 to receive the 2016-17 influenza vaccine. Preimmunization and 4-week postimmunization sera underwent strain-specific hemagglutination inhibition assay for the three vaccine strains and an additional B strain not included in the vaccine.
We randomized 172 patients and 161 (84 HD; 77 SD) were eligible for analysis. Median age was 57 years (range 18-86) and time from transplant was 38 months(range 3-1402). Types of transplant were kidney 67(39.0%), liver 38(22.1%), lung 25(14.5%), heart 23(13.3%), and combined 19(11.0%). Seroconversion to at least 1 of 3 vaccine antigens (primary outcome) was present in 78.6% vs. 55.8% in HD vs. SD vaccine respectively (p<0.001). Seroconversion to A/ H1N1, A/H3N2 and B strains were 40.5% vs. 20.5%, 57.1% vs. 32.5%, and 58.3% vs. 41.6% in HD vs. SD vaccine (p=0.006, 0.002, 0.028 respectively). Post-immunization geometric mean titers of A/H1N1, A/H3N2, and B strains were significantly higher in HD group (p=0.007, 0.002, 0.033). Independent factors associated with seroconversion to at least one vaccine strain were the use of HD vaccine and being on mycophenolate doses less than 2g daily (p=0.003, 0.013 respectively). Seroconversion rate to the B strain not included in the trivalent study vaccine was also higher in HD vaccine group (33.3% vs. 14.1%, p=0.004). Local and systemic adverse events were similar for the two vaccines. Biopsy-proven rejection was seen in 3.4% vs. 1.2% in HD vs. SD groups respectively (p=0.62). Two patients in the SD vaccine group and one in the HD group developed influenza infection during followup.
High-dose vaccine demonstrated significantly better immunogenicity than SD vaccine in adult transplant recipients and may be the preferred influenza vaccine for this population.
M. Shiotsuka, None
J. Slomovic, None
K. Hoschler, None
V. Ferreira, None
P. Ashton, None
C. Rotstein, None
L. Lilly, None
J. Schiff, None
L. Singer, None
D. Kumar, Sanofi: Speaker's Bureau , Speaker honorarium
Pfizer: Speaker's Bureau , Speaker honorarium
GSK: Grant Investigator , Grant recipient