Researchers from
CEA-Irig have adapted an innovative protein-based vaccine approach originally developed for HIV to the SARS-CoV-2 setting. Their study method involved coating lipid vesicles with synthetic SARS-CoV-2 spike (S) proteins. Modified in this manner, the vesicles resemble viral particles in both size and surface features. To stabilize the three-dimensional structure of the S protein for long-term storage, the team employed formaldehyde cross-linking, a technique used frequently in clinically-approved vaccines.
Their synthetic lipid vesicles were tested in a preclinical COVID-19 model developed by CEA-Jacob's Infectious Disease Models and Innovative Therapies division (
IDMIT). In that model, the team showed that complete vaccination resulted in "sterilizing" immunity, that is, no viral replication was observed during infection in the vaccinated group as opposed to the unvaccinated control group.
Beyond CEA-Irig and CEA-Jacob, the study also benefited from the participation of the University of Amsterdam (Netherlands) and the Institut Pasteur.