Multivalent Exosome Based Protein Vaccine: A "Mix and Match" Approach to Epidemic Viruses' Challenges

Area of Science:

• Vaccinology
• Immunology
• Nanotechnology

Background:

• Endemic viral threats necessitate rapid and effective vaccine development.
• Existing vaccine platforms may not meet the speed and efficacy demands for emerging viruses.

Purpose of the Study:

• To evaluate the StealthX™ exosome platform for rapid vaccine development against endemic viruses.
• To assess the immunogenicity of exosome-presented viral antigens and the potential for multivalent vaccine formulations.

Main Methods:

• Engineered exosomes (StealthX™) to display Influenza H3, SARS-CoV-2 Delta spike, or RSV fusion proteins.
• Administered exosomes expressing single or multiple antigens to mice.
• Assessed humoral and cellular immune responses post-vaccination.

Main Results:

• Exosomes displaying individual antigens induced potent humoral and cellular immunity in mice, even at nanogram protein doses without adjuvant.
• A multivalent 'mix and match' vaccine combining three antigen-presenting exosomes elicited a robust immune response against all three antigens.
• The trivalent cocktail vaccine's immune response magnitude was comparable to single-antigen vaccines.

Conclusions:

• The StealthX™ exosome platform effectively presents viral antigens, eliciting strong immune responses.
• This platform demonstrates significant potential for the rapid development of novel, multivalent vaccines against rapidly evolving viral infections.