Abstract
As the emerging variants of SARS-CoV-2 continue to drive the worldwide pandemic, there is a constant demand for vaccines that offer more effective and broad-spectrum protection. Here, we report a circular RNA (circRNA) vaccine that elicited potent neutralizing antibodies and T cell responses by expressing the trimeric RBD of the spike protein, providing robust protection against SARS-CoV-2 in both mice and rhesus macaques. Notably, the circRNA vaccine enabled higher and more durable antigen production than the 1mΨ-modified mRNA vaccine and elicited a higher proportion of neutralizing antibodies and distinct Th1-skewed immune responses. Importantly, we found that the circRNA RBD-Omicron vaccine induced effective neutralizing antibodies against the Omicron but not the Delta variant. In contrast, the circRNA RBD-Delta vaccine protected against both Delta and Omicron or functioned as a booster after two doses of either native- or Delta-specific vaccination, making it a favorable choice against the current variants of concern (VOCs) of SARS-CoV-2.
Keywords: COVID-19; Delta; Omicron; SARS-CoV-2; circRNA vaccine; circular RNA; mRNA vaccine; vaccine; variant of concern.
【저자키워드】 COVID-19, SARS-CoV-2, Vaccine, mRNA vaccine, Delta, omicron, variant of concern, circRNA vaccine, circular RNA, 【초록키워드】 neutralizing antibody, vaccination, Neutralizing antibodies, mRNA vaccine, variant, variants of concern, omicron, delta variant, Spike protein, Antigen, RNA, T cell, mice, mRNA, immune responses, T cell responses, VOCs, T cell response, booster, rhesus macaques, dose, worldwide pandemic, offer, variants of SARS-CoV-2, effective, trimeric RBD, robust, proportion, the spike protein, expressing, elicited, Th1-skewed immune responses, 【제목키워드】 RNA vaccine, Circular,