 The study assesses the immunogenicity and safety of H7N9 vaccines through meta-analyses of randomized clinical trials, finding that adjuvant vaccines with Iscomatrix, MF59, AS03, or aluminum adjuvants improve immune responses effectively, while non-aluminum adjuvants save vaccine dose. The study concludes that H7N9 influenza vaccines with adjuvant may be the optimal available option in an influenza pandemic at present. This article was authored by Dan Jing, Facial GAO, Cheng Jiao, and others.