Development and Preclinical Evaluation of Virus Like Particle Vaccine
Against COVID-19 Infection
Abstract
Background Vaccines that incorporate multiple SARS-CoV-2
antigens can further broaden the breadth of virus-specific cellular and
humoral immunity. This study describes the development and
immunogenicity of SARS-CoV-2 VLP vaccine that incorporates the 4
structural proteins of SARS-CoV-2. Methods VLPs were generated
in transiently transfected HEK293 cells, purified by multimodal
chromatography and characterized by tunable resistive pulse sensing,
AFM, SEM, and TEM. Immunoblotting studies verified the protein
identities of VLPs. Cellular and humoral immune responses of immunized
animals demonstrated the immune potency of the formulated VLP vaccine.
Results Transiently transfected HEK293 cells reproducibly
generated vesicular VLPs that were similar in size to and expressing all
four structural proteins of SARS-CoV-2. Alum adsorbed, K3-CpG ODN
adjuvanted VLPs elicited high titer anti-S, anti-RBD, anti-N IgG,
triggered multifunctional Th1 biased T cell responses, reduced virus
load and prevented lung pathology upon live virus challenge in
vaccinated animals. Conclusion These data suggest that VLPs
expressing all four structural protein antigens of SARS-CoV-2 are
immunogenic and can protect animals from developing COVID-19 infection
following vaccination.