A case of H7N9 influenza virus infection was first identified in China in 2013. This virus is considered to have high pandemic potential. Here, we developed a H7N9 influenza vaccine containing an aluminium adjuvant and evaluated the safety and immunogenicity of the vaccine.
From October 2017 through August 2018, we conducted a randomized, double-blind, single-centre phase I clinical trial in China among 360 participants aged 12 years or older. All participants received 2-doses of the vaccine (7.5, 15 or 30μg hemagglutinin antigen) or placebo at an interval of 21 days. Adverse event data were collected for 30 days after vaccination. Serum samples were collected on days 0, 21 and 42 for the hemagglutinin inhibition (HI) antibody assay.
A total of 347 participants (347/360, 96.4%) completed the study. The proportions of vaccine-related AEs after one injection were 56.7% (34/60) in the 7.5 μg group, 86.7% (52/60) in the 15μg group and 86.7% (52/60) in the 30μg group. The proportions of AEs after two injections were less than those reported after the first dose. None of the serious adverse events were related to the vaccine. After receiving 2-doses 7.5μg vaccine, the proportion of participants achieving an HI titer of 40 or higher was 98.2% (55/56, 95%CI, 72.3∼100.0%), with a geometric mean titers (GMTs) of 192.6 (95%CI, 162.9∼227.8).
The alum-adjuvanted H7N9 whole-virion inactivated vaccine was safe and strongly immunogenic in a population aged 12 years and older. THIS TRIAL IS REGISTERED AT CLINICALTRIALS.GOV: NCT03369808.

Copyright © 2020. Published by Elsevier Ltd.