Potentiating the cross-reactive IFN-γ T cell and polyfunctional T cell responses by heterologous GX-19N DNA booster in mice primed with either a COVID-19 mRNA vaccine or inactivated vaccine

Seo, Y. B.; Ko, A.; Shin, D.; Kim, J.; Suh, Y. S.; Na, J.; Ryu, J. I.; Sung, Y. C.

doi:10.1101/2022.05.29.493923

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bioRxiv · 10.1101/2022.05.29.493923

Potentiating the cross-reactive IFN-γ T cell and polyfunctional T cell responses by heterologous GX-19N DNA booster in mice primed with either a COVID-19 mRNA vaccine or inactivated vaccine

Seo, Y. B.·Ko, A.·Shin, D.·Kim, J.·Suh, Y. S.·Na, J.·Ryu, J. I.·Sung, Y. C.

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Abstract

Waning vaccine-induced immunity, coupled with the emergence of SARS-CoV-2 variants, has inspired the widespread implementation of COVID-19 booster vaccinations. Here, we evaluated the potentials of the GX-19N DNA vaccine as a heterologous booster to enhance the protective immune response to SARS-CoV-2 in mice primed with either an inactivated virus particle (VP) or mRNA vaccine. We found that in the VP-primed condition, GX-19N enhanced the response of both vaccine-specific antibodies and cross-reactive T-cells to the SARS-CoV-2 variant of concern (VOC) compared to the homologous VP vaccine prime-boost. Under the mRNA-primed condition, GX-19N induced higher vaccine-induced T-cell responses but lower antibody responses than the homologous mRNA vaccine prime-boost. Furthermore, heterologous GX-19N boost induced higher S-specific polyfunctional CD4+ and CD8+ T cell responses than the homologous VP or mRNA prime-boost vaccinations. Our results provide new insights into booster vaccination strategies for the management of novel COVID-19 variants.

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Seo, Y. B., Ko, A., Shin, D., Kim, J., Suh, Y. S., Na, J., Ryu, J. I., Sung, Y. C.. 2022-05-30. Potentiating the cross-reactive IFN-γ T cell and polyfunctional T cell responses by heterologous GX-19N DNA booster in mice primed with either a COVID-19 mRNA vaccine or inactivated vaccine. https://doi.org/10.1101/2022.05.29.493923

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