Immunogenicity and safety of an inactivated quadrivalent influenza vaccine: a randomized, double-blind, controlled phase III clinical trial in children aged 6-35 months in China

• Main Authors: Yuemei Hu (Author), Ming Shao (Author), Yuansheng Hu (Author), Qi Liang (Author), Ningning Jia (Author), Kai Chu (Author), Li Xu (Author), Jing Li (Author), Changgui Li (Author), Fengcai Zhu (Author)
• Format: Book
• Published: Taylor & Francis Group, 2020-07-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.
• Notes: 2164-5515; 2164-554X; 10.1080/21645515.2020.1721994
• Keywords: quadrivalent influenza vaccine; immunogenicity; safety; children; Immunologic diseases. Allergy; RC581-607; Therapeutics. Pharmacology; RM1-950
• Source: Human Vaccines & Immunotherapeutics, Vol 16, Iss 7, Pp 1691-1698 (2020)

Mismatch between circulating influenza B viruses and vaccine strains occurs frequently. In a randomized, double-blind, controlled phase III clinical study, healthy children aged 6-35 months were randomized into three groups at a ratio of 2:1:1, received two doses of quadrivalent influenza vaccines (QIVs) or licensed trivalent influenza vaccines (TIVs). The primary objective was to evaluate the non-inferiority immunogenicity of QIV compared with the two TIVs, containing B/Victoria or B/Yamagata strain. Safety information was collected for 28 days after each vaccination. Serious adverse events (SAEs) were monitored for 6 months after the second vaccination. A total of 2146 subjects (QIV: 1069, TIV-Vic: 540, TIV-Yam: 537) were enrolled in this study. QIV was found non-inferior to TIVs for shared strains (A/H1N1 and A/H3N2) and corresponding BY strain based on hemagglutination inhibition (HI) antibodies 28 days after the second dose of vaccination. The resulted geometric mean titer (GMT) ratios (QIV/TIV) were 0.98 (0.89, 1.07) for H1N1, 0.95 (0.85, 1.05) for H3N2 and 0.89 (0.81, 0.98) for BY. And the seroconversion rate differences (QIV-TIV) were −0.46% (−3.24%, 2.31%) for H1N1, −1.95% (−5.54%, 1.65%) for H3N2 and −3.58% (−8.11%, 0.95%) for BY. The BV strain in QIV did not reach the non-inferiority criteria, with GMT of 1:52.25 (vs. 1:61.02 of TIV-Vic) and seroconversion rate of 59.49% (vs. 66.85% of TIV-Vic). No increased safety concerns occurred in QIV group. Candidate QIV can provide good protection for children aged 6 to 35 months, and its immunogenicity and safety were proved. Clinical Trials Registration ClinicalTrials.gov number: NCT03859141.