CpG 684: an effective adjuvant for the inactivated COVID-19 vaccine in mice

Jiandong Liu; Tianle Cang; Congli Jiang; Kelei Li; Siyuan Liu; Haixin Wang; Meirong Wang; Yan Chen; Yan Shao; Jiankai Liu

doi:10.2217/fvl-2022-0172

CpG 684: an effective adjuvant for the inactivated COVID-19 vaccine in mice

Future Virol. 2023 May;18(7):403-410. doi: 10.2217/fvl-2022-0172. Epub 2023 Jun 1.

Authors

Affiliations

¹ Beijing Minhai Biotechnology Co. Ltd, Beijing, 102600, China.
² Shenzhen Kangtai Biological Products Co., Ltd, Guangzhou, Shenzhen, 518000, China.
³ Jiangsu Taipuriu Biotechnology Co., Ltd, Taizhou Pharmaceutical City, Jiangsu, 225300, China.

Abstract

Aim: This study used CpG 684 as adjuvant of inactivated COVID-19 vaccine to detect a humoral and cellular immune response in mice.

Materials & methods: We used 10 and 20 µg CpG 684 as adjuvants of an inactivated COVID-19 vaccine to immunize mice. IgG, IgG1, IgG2a, IgG2b and IgM binding antibodies were detected in serum by ELISA. The IFN-γ cytokine was detected by ELISPOT.

Results: CpG 684 improved spike-specific IgG and IgM subtype binding antibodies and increased the neutralizing antibody titer against prototype, Delta and Beta strains. CpG 684 also improved cellular immune response.

Conclusion: CpG 684 is an effective adjuvant for inactivated COVID-19 vaccine.

Keywords: CpG; SARS-COV-2; neutralizing antibody; vaccine; variants.