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

Abstract

This study used CpG 684 as adjuvant of inactivated COVID-19 vaccine to detect a humoral and cellular immune response in mice. We used 10and 20µg 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-γcytokine was detected by ELISPOT. 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. CpG 684 is an effective adjuvant for inactivated COVID-19 vaccine.