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bioRxiv · 10.1101/2022.09.22.508999

Triple COVID-19 vaccination induces humoral and cellular immunity to SARS-CoV-2 with cross-recognition of the Omicron variant and IgA secretion

Ruhl, L.·Kuehne, J. F.·Beushausen, K.·Keil, J.·Christoph, S.·Sauer, J.·Falk, C. S.
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Abstract

COVID-19 vaccination is the leading strategy to prevent severe courses after SARS-CoV-2 infection. In our study, we analyzed humoral and cellular immune responses in detail to three consecutive homologous or heterologous COVID-19 vaccinations. All individuals (n=20) responded to vaccination with increasing S1- /RBD-/S2-specific IgG levels, whereas specific plasma IgA displayed individual variability. The third dose increased antibody inhibitory capacity (AIC) against immune-escape variants Beta and Omicron independently from age. The mRNA-primed vaccination induced IgG and IgA immunity more efficiently, whereas vector-primed individuals displayed higher levels of memory T and B cells. Vaccinees showed a SARS-CoV-2-specific T cell responses, which were further improved and specified after Omicron breakthrough infections in parallel to appearance of new variant-specific antibodies. In conclusion, the third vaccination was essential to increase IgG levels, mandatory to boost AIC against immune-escape variants and induced SARS-CoV-2-specific T cells. Breakthrough infection with Omicron generates additional spike specificities covering all known variants.

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Ruhl, L., Kuehne, J. F., Beushausen, K., Keil, J., Christoph, S., Sauer, J., Falk, C. S.. 2022-09-22. Triple COVID-19 vaccination induces humoral and cellular immunity to SARS-CoV-2 with cross-recognition of the Omicron variant and IgA secretion. https://doi.org/10.1101/2022.09.22.508999

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