Influenza virus vaccine(ID Biomedical Corporation)

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

We conducted a randomized, double-blind trial to compare the safety and immunogenicity of the 2016-2017 high-dose (HD; FluzoneHD, Sanofi) vs SD (Fluviral, GSK) influenza vaccine in adult SOTRs. Preimmunization and 4-week postimmunization sera underwent strain-specific hemagglutination inhibition assay.

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 groups (P < .001), respectively. Seroconversions 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 groups (P = .006, P = .002, P = .028, respectively). Post-immunization geometric mean titers of A/H1N1, A/H3N2, and B strains were significantly higher in the HD group (P = .007, P = .002, P = .033). Independent factors associated with seroconversion to at least 1 vaccine strain were the use of HD vaccine (odds ratio [OR], 3.23; 95% confidence interval [CI], 1.56-6.67) and use of mycophenolate doses <2 g daily (OR, 2.76; 95% CI, 1.12-6.76).

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

NCT03139565.

Many Canadians received a novel AS03-adjuvanted vaccine during the 2009 influenza A/H1N1 pandemic. Longer term implications of adjuvant use were unclear: would anti-H1N1 immune responses persist at high levels and, if so, could that result in increased or unusual adverse effects upon re-exposure to H1N1pdm09 antigen in the trivalent influenza vaccine (TIV) for 2010-11? To answer these questions, adults given AS03-adjuvanted H1N1pdm09 vaccine (Arepanrix®, GSK Canada) 9-10 mo earlier were enrolled in an evaluator-blinded, crossover trial to receive 2010-2011 non-adjuvanted TIV (Fluviral®, GSK Canada) and placebo 10 d apart, in random order. Adverse effects were monitored for 7 d after each injection. Vaccine-attributable adverse event (VAAE) rates were calculated by subtracting rates after placebo from those after vaccine. Blood was obtained pre-vaccination and 21-30 d afterward to measure hemagglutination inhibiting antibody titers. In total, 326 participants were enrolled and 321 completed the study. VAAE rates were low except for myalgia (18.6%) and injection site pain (63.2%). At baseline, H1N1pdm09 titers ≥ 40 were present in 176/325 subjects (54.2%, 95% confidence interval 48.6, 59.7), with a geometric mean titer (GMT) of 37.4 (95% CI 32.8, 42.6). Post-immunization, 96.0% (95% CI 92.3, 97.8) had H1N1pdm09 titers ≥ 40, with GMT of 167.4 (95% CI 148.7, 188.5). Responses to both influenza A strains in TIV were similar, implying no lasting effect of adjuvant exposure. In summary, titers ≥ 40 persisted in only half the participants 9-10 mo after adjuvanted pandemic vaccine but were restored in nearly all after TIV vaccination, with minimal increase in adverse effects.