Effect of Different Adjuvants on Immune Responses Elicited by Protein-Based Subunit Vaccines against SARS-CoV-2 and Its Delta Variant
Naru Zhang,
Qianting Ji,
Zezhong Liu,
Kaiming Tang,
Yubin Xie,
Kangchen Li,
Jie Zhou,
Sisi Li,
Haotian Shang,
Zecan Shi,
Tianyu Zheng,
Jiawei Yao,
Lu Lu,
Shuofeng Yuan,
Shibo Jiang
Affiliations
Naru Zhang
School of Medicine and Waikato Joint Institute, Zhejiang University City College, Hangzhou 310015, China
Qianting Ji
School of Medicine and Waikato Joint Institute, Zhejiang University City College, Hangzhou 310015, China
Zezhong Liu
Key Laboratory of Medical Molecular Virology (MOE/NHC/CAMS), Shanghai Frontiers Science Center of Pathogenic Microbes and Infection, School of Basic Medical Sciences, Shanghai Institute of Infectious Disease and Biosecurity, Fudan University, Shanghai 200032, China
Kaiming Tang
Department of Microbiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
Yubin Xie
Department of Microbiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
Kangchen Li
School of Medicine and Waikato Joint Institute, Zhejiang University City College, Hangzhou 310015, China
Jie Zhou
Key Laboratory of Medical Molecular Virology (MOE/NHC/CAMS), Shanghai Frontiers Science Center of Pathogenic Microbes and Infection, School of Basic Medical Sciences, Shanghai Institute of Infectious Disease and Biosecurity, Fudan University, Shanghai 200032, China
Sisi Li
School of Medicine and Waikato Joint Institute, Zhejiang University City College, Hangzhou 310015, China
Haotian Shang
School of Medicine and Waikato Joint Institute, Zhejiang University City College, Hangzhou 310015, China
Zecan Shi
School of Medicine and Waikato Joint Institute, Zhejiang University City College, Hangzhou 310015, China
Tianyu Zheng
School of Medicine and Waikato Joint Institute, Zhejiang University City College, Hangzhou 310015, China
Jiawei Yao
School of Medicine and Waikato Joint Institute, Zhejiang University City College, Hangzhou 310015, China
Lu Lu
Key Laboratory of Medical Molecular Virology (MOE/NHC/CAMS), Shanghai Frontiers Science Center of Pathogenic Microbes and Infection, School of Basic Medical Sciences, Shanghai Institute of Infectious Disease and Biosecurity, Fudan University, Shanghai 200032, China
Shuofeng Yuan
Department of Microbiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
Shibo Jiang
Key Laboratory of Medical Molecular Virology (MOE/NHC/CAMS), Shanghai Frontiers Science Center of Pathogenic Microbes and Infection, School of Basic Medical Sciences, Shanghai Institute of Infectious Disease and Biosecurity, Fudan University, Shanghai 200032, China
The global pandemic of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become more serious because of the continuous emergence of variants of concern (VOC), thus calling for the development of broad-spectrum vaccines with greater efficacy. Adjuvants play important roles in enhancing the immunogenicity of protein-based subunit vaccines. In this study, we compared the effect of three adjuvants, including aluminum, nanoparticle manganese and MF59, on the immunogenicity of three protein-based COVID-19 vaccine candidates, including RBD-Fc, RBD and S-trimer. We found that the nanoparticle manganese adjuvant elicited the highest titers of SARS-CoV-2 RBD-specific IgG, IgG1 and IgG2a, as well as neutralizing antibodies against infection by pseudotyped SARS-CoV-2 and its Delta variant. What is more, the nanoparticle manganese adjuvant effectively reduced the viral load of the authentic SARS-CoV-2 and Delta variant in the cell culture supernatants. These results suggest that nanoparticle manganese, known to facilitate cGAS-STING activation, is an optimal adjuvant for protein-based COVID-19 subunit vaccines.
