A Double Blind Randomized Trial of High Dose vs. Standard Dose Influenza Vaccine in Adult Solid Organ Transplant Recipients

Abstract

Background

The annual standard dose influenza vaccine has suboptimal immunogenicity in solid organ transplant recipients (SOTR). Influenza vaccine containing higher doses of antigens may lead to greater immunogenicity in this population.

Methods

We conducted a randomized, double blind trial comparing the safety and immunogenicity of the 2016-17 high dose (HD; FluzoneHD,Sanofi) versus standard dose (SD; Fluviral,GSK) influenza vaccine in adult SOTR. Preimmunization and 4-week postimmunization sera underwent strain-specific hemagglutination inhibition assay.

Results

We enrolled 172 patients who received study vaccine and 161 (84 HD; 77 SD) were eligible for analysis. Seroconversion to at least 1 of 3 vaccine antigens 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 (OR 3.23, 95% CI 1.56-6.67) and use of mycophenolate doses less than 2g daily (OR 2.76, 95% CI 1.12-6.76).

Conclusions

High-dose vaccine demonstrated significantly better immunogenicity than SD vaccine in adult transplant recipients and may be the preferred influenza vaccine for this population.