Effectiveness of Booster Doses of the SARS-CoV-2 Inactivated Vaccine KCONVAC against the Mutant Strains
Chanchan Xiao,
Jun Su,
Chanjuan Zhang,
Boya Huang,
Lipeng Mao,
Zhiyao Ren,
Weibin Bai,
Huayu Li,
Guomin Lei,
Jingshan Zheng,
Guobing Chen,
Xiaofeng Liang,
Congling Qiu
Affiliations
Chanchan Xiao
Department of Microbiology and Immunology, Institute of Geriatric Immunology, School of Medicine, Jinan University, Guangzhou 510630, China
Jun Su
Affiliated Huaqiao Hospital, Jinan University, Guangzhou 510630, China
Chanjuan Zhang
Department of Microbiology and Immunology, Institute of Geriatric Immunology, School of Medicine, Jinan University, Guangzhou 510630, China
Boya Huang
Department of Systems Biomedical Sciences, School of Medicine, Jinan University, Guangzhou 510630, China
Lipeng Mao
Department of Systems Biomedical Sciences, School of Medicine, Jinan University, Guangzhou 510630, China
Zhiyao Ren
Department of Systems Biomedical Sciences, School of Medicine, Jinan University, Guangzhou 510630, China
Weibin Bai
Department of Food Science and Engineering, Institute of Food Safety and Nutrition, Guangdong Engineering Technology Center of Food Safety Molecular Rapid Detection, Jinan University, Guangzhou 510630, China
Huayu Li
Shenzhen Kangtai Biological Products Co., Ltd., Shenzhen 518000, China
Guomin Lei
Shenzhen Kangtai Biological Products Co., Ltd., Shenzhen 518000, China
Jingshan Zheng
Shenzhen Kangtai Biological Products Co., Ltd., Shenzhen 518000, China
Guobing Chen
Department of Microbiology and Immunology, Institute of Geriatric Immunology, School of Medicine, Jinan University, Guangzhou 510630, China
Xiaofeng Liang
Department of Microbiology and Immunology, Institute of Geriatric Immunology, School of Medicine, Jinan University, Guangzhou 510630, China
Congling Qiu
Department of Microbiology and Immunology, Institute of Geriatric Immunology, School of Medicine, Jinan University, Guangzhou 510630, China
As the COVID-19 epidemic progresses with the emergence of different SARS-CoV-2 variants, it is important to know the effectiveness of inactivated SARS-CoV-2 vaccines against the variants. To maximize efficiency, a third boost injection of the high-dose SARS-CoV-2 inactivated vaccine KCONVAC was selected for investigation. In addition to the ancestral strain, KCONVAC boost vaccination induced neutralizing antibodies and antigen-specific CD8 T cells to recognize several variants, including B.1.617.2 (Delta), B.1.1.529 (Omicron), B.1.1.7 (Alpha), B.1.351 (Beta), P.3, B.1.526.1 (Lota), B.1.526.2, B.1.618, and B.1.617.3. Both humoral and cellular immunity against variants were lower than those of ancestral variants but continued to increase from day 0 to day 7 to day 50 after boost vaccination. Fifty days post-boost, the KCONVAC-vaccinated CD8 T-cell level reached 1.23-, 2.59-, 2.53-, and 1.01-fold that of convalescents against ancestral, Delta, Omicron and other SARS-CoV-2 variants, respectively. Our data demonstrate the importance of KCONVAC boosters to broaden both humoral and cellular immune responses against SARS-CoV-2 variants.
