Several different vaccines have been produced for human use to prevent the highly pathogenic H5N1 influenza. Some studies reported that the clinical effectiveness of influenza vaccines in older adults might be lower than in younger adults. In this study, a meta-analysis of the immunogenicity of H5N1 influenza vaccines in elderly adults was performed. Researchers conducted database searches in EMBASE, PubMed, the Cochrane Library, Chinese VIP, Wanfang, and CBM. A total of 3951 elderly adults from 10 articles were included in the meta-analysis. Compared to a single dose, two doses of H5N1 vaccines resulted in higher seroconversion and seroprotection. There were significant increases in the SCRs and SPRs after two immunizations for all groups treated with adjuvanted vaccines. After treatment with the 7.5 μg of OE-adjuvanted vaccines, the most commonly reported adverse events were injection site pain, swelling, and erythema, with the incidence of 32%, 3%, and 2%, respectively, and no serious adverse events were found. These data demonstrate that two doses of 7.5 µg of OE-adjuvanted H5N1 vaccine are well tolerated and induce a robust antibody response in elderly adults.
Reference: https://www.tandfonline.com/doi/full/10.1080/21645515.2020.1777822
