Torresi, J.; Edeling, M. A.; Earnest-Silveira, L.; Carrera, J.; Yap, A. H. Y.; Hans, D.

We aimed to study the stability of a {beta}-SARS-CoV-2 virus-like particle (VLP) vaccine in a series of preliminary experiments using select stabilising excipients. {beta}-SARS-CoV-2 VLPs were produced and purified using established methodologies. The thermostability of VLPs was tested at 4{degrees}C and -30{degrees}C in the presence or absence of stabilizers polysorbate 80, sorbitol or L-histidine in the presence of a physiological NaCl concentration of 137mM. The integrity of VLPs was assessed using ELISA, Western immunoblot and dynamic light scatter (DLS). {beta}-SARS-CoV-2 VLPs were stable at 4{degrees}C for 14 days and the addition of stabilizing excipients improved stability compared to VLPs in PBS alone. Storage of VLPs at -80{degrees}C maintained particle integrity by DLS analysis for up to 2 years. Excipients helped to maintain the immunogenicity of the VLPs by ELISA and Western immunoblot and DLS analysis revealed that VLPs retained their particulate structure.