Virus-Mimetic Vaccine Based on Self-Assembled Antigen-Polymer Conjugates Eliciting Effective Immunity Against Influenza Virus

Vaccines have been providing humankind with the ability to defend against infectious diseases. However, existing vaccines face obstacles such as a risk of adverse effects and limited immunogenicity. In the present work, we developed a self-assembled vaccine (SAV) platform based on antigen conjugated with an amphiphilic block copolymer, mPEG-b-PLA-NHS. To improve subunit vaccine immunity, SAV was designed to be nanoscale for effective antigen transport and to display repetitive antigens on its surface to trigger immune cells via multivalent recognition. SAV demonstrated improved cellular uptake by dendritic cells (DCs), hence promoting an efficient activation of the adaptive immune system. In vivo study revealed that SAV induced high levels of IgG, IgG1, and IgG2, indicating effective B cell activation and T cell-mediated immunological response. In addition, we confirmed that SAV containing hemagglutinin (HA) effectively prevented mice from mortality due to influenza virus infection. These results imply that the self-assembled nanosystem constituted of antigen-polymer conjugate can serve as an effective and versatile vaccine platform.