CoVac501, a self-adjuvanting peptide vaccine conjugated with TLR7 agonists, against SARS-CoV-2 induces protective immunity

Long, Y.; Sun, J.; Liu, T.; Tang, F.; Zhang, X.; Qin, Q.; Miao, Y.; Pan, X.; An, Q.; Qin, M.; Tong, X.; Peng, X.; Yu, P.; Zhu, P.; Zhu, W.; Zhang, Y.; Zhang, L.; Xiao, G.; Zuo, J.; Tang, W.; Zhou, J.; Xu, Z.; Gan, Y.; Ren, J.; Huang, W.; Jin, G.; Gong, L.

doi:10.1101/2021.04.10.439275

bioRxiv · 10.1101/2021.04.10.439275

CoVac501, a self-adjuvanting peptide vaccine conjugated with TLR7 agonists, against SARS-CoV-2 induces protective immunity

Long, Y.·Sun, J.·Liu, T.·Tang, F.·Zhang, X.·Qin, Q.·Miao, Y.·Pan, X.·An, Q.·Qin, M.·Tong, X.·Peng, X.·Yu, P.·Zhu, P.·Zhu, W.·Zhang, Y.·Zhang, L.·Xiao, G.·Zuo, J.·Tang, W.·Zhou, J.·Xu, Z.·Gan, Y.·Ren, J.·Huang, W.·Jin, G.·Gong, L.

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Abstract

Safe, economical and effective vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are needed to achieve adequate herd immunity and halt the pandemic. We have constructed a novel SARS-CoV-2 vaccine, CoVac501, which is a self-adjuvanting peptide vaccine conjugated with Toll-like receptor 7 (TLR7) agonists. The vaccine contains two immunodominant peptides screened from receptor-binding domain (RBD) and is fully chemically synthesized. And the vaccine has optimized nanoemulsion formulation, outstanding stability and safety. In non-human primates (NHPs), CoVac501 elicited high and persistent titers of RBD-specific and protective neutralizing antibodies (NAbs), which were also effective to RBD mutations. CoVac501 was found to elicit the increase of memory T cells, antigen-specific CD8+ T cell responses and Th1-biased CD4+ T cell immune responses in NHPs. More importantly, the sera from the immunized NHPs can prevent infection of live SARS-CoV-2 in vitro. One-Sentence SummaryA novel SARS-CoV-2 vaccine we developed, CoVac501, which is a fully chemically synthesized and self-adjuvanting peptides conjugated with TLR7 agonists, can induce high-efficient humoral and cellular immune responses against SARS-CoV-2.

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Long, Y., Sun, J., Liu, T., Tang, F., Zhang, X., Qin, Q., Miao, Y., Pan, X., An, Q., Qin, M., Tong, X., Peng, X., Yu, P., Zhu, P., Zhu, W., Zhang, Y., Zhang, L., Xiao, G., Zuo, J., Tang, W., Zhou, J., Xu, Z., Gan, Y., Ren, J., Huang, W., Jin, G., Gong, L.. 2021-04-11. CoVac501, a self-adjuvanting peptide vaccine conjugated with TLR7 agonists, against SARS-CoV-2 induces protective immunity. https://doi.org/10.1101/2021.04.10.439275

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