A spray dried replicon vaccine platform for pandemic response

Area of Science:

• Vaccinology
• Nanotechnology
• Biotechnology

Background:

• The COVID-19 and H5N1 threats necessitate thermostable vaccines for rapid pandemic response.
• A previously developed nanostructured lipid carrier (NLC) replicon vaccine platform offers rapid, scalable manufacturing.
• Spray drying presents a cost-effective, scalable alternative to lyophilization for vaccine desiccation.

Purpose of the Study:

• To demonstrate the feasibility of spray drying an H5N1 avian influenza replicon-NLC vaccine.
• To enhance the long-term thermostability and immunogenicity of the vaccine.
• To explore the potential for dry powder vaccine delivery via nasal or pulmonary routes.

Main Methods:

• Screening of glass-forming disaccharide excipients for spray drying compatibility.
• Optimization of spray drying conditions for the replicon-NLC vaccine complex.
• Assessment of chemical stability, immunogenicity, and aerodynamic particle size of the spray-dried vaccine.

Main Results:

• Successful spray drying of the H5N1 replicon-NLC vaccine, yielding chemically stable powders for at least one month at 40°C.
• Maintained vaccine immunogenicity for at least three months at 4°C when reconstituted and administered to mice.
• Demonstrated control over aerodynamic particle size for potential dry powder inhalation delivery.

Conclusions:

• Spray drying is a viable method for producing a thermostable, immunogenic replicon-NLC vaccine.
• This technology enhances pandemic preparedness through improved vaccine stability and scalable manufacturing.
• The potential for dry powder delivery offers new avenues for vaccine administration.