Abstract
Avian influenza H5N1 virus continues to cause disease in poultry and humans, posing a threat to worldwide pandemic outbreak. Thus, developing a more effective vaccine against highly pathogenic H5N1 is urgently needed. Influenza virus-like particles (VLPs) have been indicated as a promising vaccine approach, and incorporation of molecular adjuvant(s) into influenza VLPs can enhance the immunogenicity. In this study, we investigated three molecular adjuvants, GM-CSF, CD40L, and flagellin (FliC), incorporated into influenza VLPs by M2 fusion and demonstrated the immune responses in BALB/c mice. Our results revealed that CD40L VLPs resulted in eliciting highest titers of total IgG, and neutralizing antibodies, indicating that CD40L VLPs were more immunogenic than the others. Thus, CD40L VLPs might be a potential candidate for influenza vaccine development in the future.