Crossprotection induced by virus-like particles containing influenza dual-hemagglutinin and M2 ectodomain

To develop an effective universal vaccine against antigenically different influenza viruses. We generated influenza virus-like particles (VLPs) expressing the H1 and H3 antigens with or without M2e5x. VLP-induced immune responses and crossprotection against H1N1, H3N2 or H5N1 viruses were assessed to evaluate their protective efficacy. H1H3M2e5x immunization elicited higher crossreactive IgG antibodies than H1H3 VLPs. Upon challenge, both VLPs enhanced lung IgG, IgA and germinal center B-cell responses compared with control. While these VLPs conferred protection, H1H3M2e5x showed greater lung viral load reduction than H1H3 VLPs with minimal body weight loss. Utilizing VLPs containing dual-hemagglutinin, along with M2e5x, can be a vaccination strategy for inducing crossprotection against influenza A viruses.