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

doi:10.3390/v14092016

Effectiveness of Booster Doses of the SARS-CoV-2 Inactivated Vaccine KCONVAC against the Mutant Strains

Viruses. 2022 Sep 12;14(9):2016. doi: 10.3390/v14092016.

Authors

Chanchan Xiao¹, Jun Su², Chanjuan Zhang^{1

3}, Boya Huang⁴, Lipeng Mao⁴, Zhiyao Ren⁴, Weibin Bai⁵, Huayu Li⁶, Guomin Lei⁶, Jingshan Zheng⁶, Guobing Chen¹, Xiaofeng Liang^{1

7}, Congling Qiu^{1

7}

Affiliations

¹ Department of Microbiology and Immunology, Institute of Geriatric Immunology, School of Medicine, Jinan University, Guangzhou 510630, China.
² Affiliated Huaqiao Hospital, Jinan University, Guangzhou 510630, China.
³ Department of Pathophysiology, Key Laboratory of State Administration of Traditional Chinese Medicine of the People's Republic of China, School of Medicine, Jinan University, Guangzhou 510630, China.
⁴ Department of Systems Biomedical Sciences, School of Medicine, Jinan University, Guangzhou 510630, China.
⁵ 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.
⁶ Shenzhen Kangtai Biological Products Co., Ltd., Shenzhen 518000, China.
⁷ Jinan University-BioKangtai Vaccine Institute, School of Medicine, Jinan University, Guangzhou 510630, China.

Abstract

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.

Keywords: SARS-CoV-2; cellular immune responses; inactivated vaccine KCONVAC; variants.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Antibodies, Neutralizing
Antibodies, Viral
COVID-19 Vaccines
COVID-19* / prevention & control
Humans
SARS-CoV-2 / genetics
Vaccines, Inactivated
Viral Vaccines*

Substances

Antibodies, Neutralizing
Antibodies, Viral
COVID-19 Vaccines
SARS-CoV-2 inactivated vaccines
Vaccines, Inactivated
Viral Vaccines

Supplementary concepts

SARS-CoV-2 variants

Grants and funding

This work was supported by grants from the Natural Science Foundation of China (U1801285 and 92169102), the Fundamental Research Funds for the Central Universities (21622108), the fellowship of China Postdoctoral Science Foundation (2021M701417), the Guang Dong Basic and Applied Basic Research Foundation (2021A1515110734), and the Initial Startup Fund of Jinan University.