ABSTRACT
SARS-CoV-2 is the underlying cause for the COVID-19 pandemic. Like most enveloped RNA viruses, SARS-CoV-2 uses a homotrimeric surface antigen to gain entry into host cells. Here we describe S-Trimer, a native-like trimeric subunit vaccine candidate for COVID-19 based on Trimer-Tag technology. Immunization of S-Trimer with either AS03 (oil-in-water emulsion) or CpG 1018 (TLR9 agonist) plus alum adjuvants induced high-level of neutralizing antibodies and Th1-biased cellular immune responses in animal models. Moreover, rhesus macaques immunized with adjuvanted S-Trimer were protected from SARS-CoV-2 challenge compared to vehicle controls, based on clinical observations and reduction of viral loads in lungs. Trimer-Tag may be an important platform technology for scalable production and rapid development of safe and effective subunit vaccines against current and future emerging RNA viruses.
Subject(s)
COVID-19 Vaccines/therapeutic use , COVID-19/immunology , COVID-19/prevention & control , SARS-CoV-2/pathogenicity , Animals , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , Blotting, Western , COVID-19/therapy , Enzyme-Linked Immunosorbent Assay , Female , Humans , Immunity, Cellular/physiology , Immunization, Passive , Immunohistochemistry , Macaca mulatta , Mice , Mice, Inbred BALB C , Microscopy, Electron , SARS-CoV-2/immunology , COVID-19 SerotherapyABSTRACT
A novel pneumonia-associated respiratory syndrome named coronavirus disease-2019 (COVID-19), which was caused by SARS-CoV-2ï¼broke out in Wuhan, China, in the end of 2019. Unfortunately, there is no specific antiviral agent or vaccine available to treat SARS-CoV-2 infections. The information regarding the immunological characteristics in COVID-19 patients remains limited. Here, we collected the blood samples from 18 healthy donors (HD) and 38 COVID-19 patients to analyze changes on γδ T cell population. In comparison with HD, the γδ T cell percentage decreased, while the activation marker CD25 expression increased in response to SARS-CoV-2 infection. Interestingly, the CD4 expression was upregulated in γδ T cells reflecting the occurrence of a specific effector cell population, which may serve as a biomarker for the assessment of SARS-CoV-2 infection.