Comparing the immunogenicity of different SARS-CoV-2 spike vaccine platforms in mice

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Presentation Time: 03:15 PM - 04:30 PM
Poster Board Number: B908
Abstract ID: 4493

Presenting Author:
Min Han Lew , Postdoctoral scholar at Northwestern Univ. Feinberg Sch. of Med.

Abstract:

Comparing the immunogenicity of different SARS-CoV-2 spike vaccine platforms in mice

Min Han Lew^1Y, Sarah Sanchez^1Y, Pablo Penaloza-MacMaster¹

¹Department of Microbiology and Immunology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611.

^YEqual contribution.

Multiple vaccine platforms have been deployed during the COVID-19 pandemic, and it is still unclear how these differ in terms of their immunogenicity and efficacy. Here, we compare the immunogenicity of different vaccine platforms in C57BL/6 mice, including Ad5-, mRNA- and protein-based regimens expressing the SARS-CoV-2 spike antigen. After vaccination with different vaccine vectors, immune responses were measured using enzyme-linked immunosorbent assays (ELISA) and tetramer binding assays to measure antibody responses and CD8 T cell responses to the SARS-CoV-2 spike protein, respectively. Immunization with Ad5 vectored vaccines elicited the highest CD8 T cell and antibody response relative to other vaccine platforms, but only when administered into Ad5 seronegative mice. However, when administered into Ad5 seropositive mice, mRNA vaccines elicited the highest immune response. These data suggest that the relative efficacy of adenovirus- or mRNA-based vaccines depends on whether the host has pre-existing immunity to the adenovirus vector itself.