Janssen Vaccines & Prevention BV, National Institutes of Health, Ragon Institute of MGH, MIT and Harvard, Henry M Jackson Foundation for the Advancement of Military Medicine, US Department of Defense, and International AIDS Vaccine Initiative.

Quadrivalent influenza vaccines (QIVs), which include both B lineage strains, are expected to provide broader protection than trivalent influenza vaccines (TIVs). The non-inferiority, immunogenicity, and safety of a cell culture-based investigational QIVc and 2 TIVs (TIV1c, TIV2c), in adults (≥18 y), were evaluated in this Phase III, double-blind, multicenter study. A total of 2680 age-stratified subjects were randomized (2:1:1) to receive 1 dose of QIVc (n = 1335), TIV1c (n = 676), or TIV2c (n = 669). TIV1c (B/Yamagata) and TIV2c (B/Victoria) differed only in B strain lineage. The primary objective was to demonstrate non-inferiority of the hemagglutinin-inhibition antibody responses of QIVc against TIVc, 22 d post-vaccination. Secondary objectives included the evaluation of immunogenicity of QIVc and TIVc in younger (≥18 – <65 y) and older (≥65 y) adults. Hemagglutinin inhibition assays were performed at days 1 and 22. Solicited local and systemic adverse events (AEs) were monitored for 7 d post-vaccination, and unsolicited AEs and serious AEs until day 181. QIVc met the non-inferiority criteria for all 4 vaccine strains and demonstrated superiority for both influenza B strains over the unmatched B strain included in the TIV1c and TIV2c, when geometric mean titers and seroconversion rates with TIVc were compared at day 22. Between 48%–52% of subjects experienced ≥1 solicited AE, the most common being injection-site pain and headache. Serious AEs were reported by ≤1% of subjects, none were vaccine-related. The results indicate that QIVc is immunogenic and well tolerated in both younger and older adults. The immunogenicity and safety profiles of QIVc and TIVc were comparable at all ages evaluated.

A potentially deadly A/H7N9 avian-origin influenza virus is currently the cause of an ongoing outbreak in China. Preparedness plans have thus been initiated to preempt the spread of this virus, which appears to have substantial pandemic potential. To effectively prevent a pandemic from unfolding, rapid production of an immunogenic vaccine with an acceptable safety profile is critical. Given the significance to public health, we are reporting immunogenicity and safety results from a phase 1 study in healthy adults administered one of four inactivated A/H7N9 vaccine formulations. Three formulations contained increasing quantities of antigen and of an oil-in-water adjuvant, MF59, and one formulation contained only the maximum dose of antigen without adjuvant. All vaccine formulations were derived using a synthetic virus seed technology in combination with a cell culture approach; together, these techniques have been shown to expedite vaccine production compared to conventional methods. Higher responses were seen with the MF59-adjuvanted versus the nonadjuvanted A/H7N9 vaccine, with significant and potentially protective immune responses after two doses in most subjects with no preexisting immunity to the H7N9 virus. Further, despite increased injection site pain and other mild effects with MF59, all formulations were well tolerated. These encouraging immunogenicity and safety data on the A/H7N9 vaccine provide a strong rationale for further clinical development. By also using synthetic seed/cell culture technology, we are now one step closer to being able to rapidly and reliably respond to a potential H7N9 pandemic using a clinically tested A/H7N9 vaccine.

The safety and immunogenicity results from this study support inclusion of the GLA-SE adjuvant in this RSV vaccine for older adults and also support assessment of the efficacy of the vaccine in a larger clinical trial. Clinicaltrials.gov NCT02115815.

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