Immunization with synthetic SARS-CoV-2 S glycoprotein virus-like particles protects Macaques from infection

Abstract

The SARS-CoV-2 pandemic causes an ongoing global health crisis, which requires efficient and safe vaccination programs. Here, we present synthetic SARS-CoV2 S glycoprotein-coated liposomes that resemble in size and surface structure virus-like particles. Soluble S glycoprotein trimers were stabilized by formaldehyde cross-linking and coated onto lipid vesicles (S-VLP). Immunization of cynomolgus macaques with S-VLPs induced high antibody titers and TH1 CD4+ biased T cell responses. Although antibody responses were initially dominated by RBD specificity, the third immunization boosted non-RBD antibody titers. Antibodies showed potent neutralization against the vaccine strain and the Alpha variant after two immunizations and robust neutralization of Beta and Gamma strains. Challenge of animals with SARS-CoV-2 protected all vaccinated animals by sterilizing immunity. Thus, the S-VLP approach is an efficient and safe vaccine candidate based on a proven classical approach for further development and clinical testing.

Medical imaging of pulmonary disease in SARS-CoV-2-exposed non-human primates

“…In general, BAL and imaging should be concurrently used with caution, as BAL may produce CXR or CT imaging artifacts when performed on consecutive days [72], interfere with pulmonary pathogenesis (within-lung spread), and potentially confound histopathology. Of the 41 NHP SARS-CoV-2 studies examined, 24 used BAL during the infection phase and included imaging [12][13][14][15][16]20,[22][23][24][27][28][29][30]33,35,50,51,53,54,56,65,73,74]. Eight included single BAL immediately before or at necropsy [12,20,22,33,54,57,65,73].…”

BioSimia, France CNRS network for nonhuman primate biomedical research in infectiology, immunology, and neuroscience

“…This is currently the case for the COVID-19/SARS-Cov2 crisis, triggering, in fact, a market competition and an international shortage of nonhuman primate models. French institutes play a significant role in the description and pursuit of therapies for COVID 19 ( Maisonnasse et al, 2020 ; Gonçalves et al, 2021 ; Naninck et al, 2022 ; Sulbaran et al, 2022 ) and in the validation of respiratory disease models ( Lemaitre et al, 2021 ).…”