The vaccinia-based Sementis Copenhagen Vector COVID-19 vaccine induces broad and durable cellular and humoral immune responses

Eldi, P.; Cooper, T. H.; Prow, N. A.; Liu, L.; Heinemann, G. K.; Zhang, V. J.; Trinidad, A. D.; Guzman-Genuino, R. M.; Wulff, P.; Hobbs, L. M.; Diener, K. R.; Hayball, J. D.

doi:10.1101/2021.09.06.459206

bioRxiv · 10.1101/2021.09.06.459206

The vaccinia-based Sementis Copenhagen Vector COVID-19 vaccine induces broad and durable cellular and humoral immune responses

Eldi, P.·Cooper, T. H.·Prow, N. A.·Liu, L.·Heinemann, G. K.·Zhang, V. J.·Trinidad, A. D.·Guzman-Genuino, R. M.·Wulff, P.·Hobbs, L. M.·Diener, K. R.·Hayball, J. D.

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Abstract

The ongoing COVID-19 pandemic perpetuated by SARS-CoV-2 variants, has highlighted the continued need for broadly protective vaccines that elicit robust and durable protection. Here, the vaccinia virus-based, replication-defective Sementis Copenhagen Vector (SCV) was used to develop a first-generation COVID-19 vaccine encoding the spike glycoprotein (SCV-S). Vaccination of mice rapidly induced polyfunctional CD8 T cells with cytotoxic activity and robust Th1-biased, spike-specific neutralizing antibodies, which are significantly increased following a second vaccination, and contained neutralizing activity against the alpha and beta variants of concern. Longitudinal studies indicated neutralizing antibody activity was maintained up to 9 months post-vaccination in both young and aging mice, with durable immune memory evident even in the presence of pre-existing vector immunity. This immunogenicity profile suggests a potential to expand protection generated by current vaccines in a heterologous boost format, and presents a solid basis for second-generation SCV-based COVID-19 vaccine candidates incorporating additional SARS-CoV-2 immunogens.

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Eldi, P., Cooper, T. H., Prow, N. A., Liu, L., Heinemann, G. K., Zhang, V. J., Trinidad, A. D., Guzman-Genuino, R. M., Wulff, P., Hobbs, L. M., Diener, K. R., Hayball, J. D.. 2021-09-07. The vaccinia-based Sementis Copenhagen Vector COVID-19 vaccine induces broad and durable cellular and humoral immune responses. https://doi.org/10.1101/2021.09.06.459206

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