Jiangsu gdk Biotechnology Co., Ltd.

This study assessed the immunogenicity and safety of a quadrivalent influenza split-virion vaccine (IIV4) in children with and without prior influenza vaccination. An open-label, phase IV clinical trial was conducted in healthy children aged 3-8 years in Pizhou, Jiangsu Province, China. Children with ≥2 doses of prior influenza vaccination (Influenza Vaccination Group) and those with no prior vaccination (Influenza Vaccine-naïve Group) were given two doses of IIV4, 4 weeks apart. The primary immunogenicity endpoints were seroprotection rates (SPRs) of hemagglutination inhibition antibody 28 days after each dose against influenza A/H1N1, A/H3N2, B/Yamagata (BY), and B/Victoria (BV). Safety endpoints included adverse events (AEs) within 28 days and serious adverse events (SAEs) within 6 months. Between September 19-25, 2021, 278 participants were screened, and 240 were enrolled (120 per group). In the Influenza Vaccination Group, SPRs after the 2nd dose were 98.28%, 92.24%, 99.14%, and 87.93%, similar to those after the 1st dose (all p > .05). In the Influenza Vaccine-naïve Group, SPRs after the 2nd dose were 99.12%, 96.49%, 99.12%, and 92.11%, significantly higher than after the 1st dose (p < .001 for all strains except BY, p = .070). Most AEs were mild or moderate, with no serious AEs related to the vaccine. Children aged 3-8 years with prior influenza vaccination need only one dose of IIV4, while those without prior vaccination require two doses. ClinicalTrials.gov, the identifier is NCT05144464.

The immunogenicity and safety of the concomitant administration of recombinant COVID-19 vaccine and quadrivalent inactivated influenza vaccine (Split Virion) (QIIV) in Chinese adults are unclear. In this open-label, randomized controlled trial, participants aged ≥ 18 years were recruited. Eligible healthy adults were randomly assigned (1:1) to receive QIIV at the same time as the first dose of COVID-19 vaccine (simultaneous-group) or 14 days after the second dose of COVID-19 vaccine (non-simultaneous-group). The primary outcome was to compare the difference in immunogenicity of QIIV (H1N1, H3N2, Yamagata, and Victoria) between the two groups. A total of 299 participants were enrolled, 149 in the simultaneous-group and 150 in the non-simultaneous-group. There were no significant differences in geometric mean titer (GMT) [H1N1: 386.4 (95%CI: 299.2-499.0) vs. 497.4 (95%CI: 377.5-655.3); H3N2: 66.9 (95%CI: 56.1-79.8) vs. 81.4 (95%CI: 67.9-97.5); Yamagata: 95.6 (95%CI: 79.0-115.8) vs. 74.3 (95%CI: 58.6-94.0); and Victoria: 48.5 (95%CI: 37.6-62.6) vs. 65.8 (95%CI: 49.0-88.4)] and seroconversion rate (H1N1: 87.5% vs. 90.1%; H3N2: 58.1% vs. 62.0%; Yamagata: 75.0% vs. 64.5%; and Victoria: 55.1% vs. 62.8%) of QIIV antibodies between the simultaneous and non-simultaneous groups. For the seroprotection rate of QIIV antibodies, a higher seroprotection rate of Yamagata antibody was observed only in the simultaneous-group than in the non-simultaneous-group [86.0% vs. 76.0%, p = .040]. In addition, no significant difference in adverse events was observed between the two groups (14.2% vs. 23.5%, p = .053). In conclusion, no immune interference or safety concerns were found for concomitant administration of COVID-19 vaccine with QIIV in adults aged ≥ 18 years.

Viruses from two antigenically distinct influenza B strains have co-circulated since the mid-1980s, yet inactivated trivalent influenza vaccines (TIVs) with either the Victoria or Yamagata lineage could only provide limited protection from influenza B strain. Quadrivalent influenza vaccine (QIV) including both influenza B lineages can improve protection against circulating influenza B viruses.

Participants >/ = 3 years of age were recruited, stratified by age, and then randomly allocated at a ratio of 2:1:1 to receive one-injection of the experimental QIV, TIV-Victoria (Vic) or TIV-Yamagata (Yam). The primary objective of this study was to demonstrate that the hemagglutination-inhibition (HI) antibodies induced by the QIV candidate are not inferior to the licensed TIVs.

First, 3661 participants received the inoculation. The QIV was found to be non-inferior to TIVs in terms of the geometric mean titers (GMTs) and seroconversion rates (SCRs) of the HI antibodies against shared strains 28 days after completion of inoculation, and was superior to the TIVs against the alternate B strain, which is absent from the TIVs. The occurrences of adverse events (AEs) post-vaccination were similar across the treatment groups.

The experimental QIV showed good immunogenicity and an acceptable safety profile.