Immune protection through long-lived plasma cells after mRNA vaccination

Researchers from Henrik Mei’s group at the DRFZ, together with colleagues from Charité, have shown that repeated mRNA vaccinations against SARS-CoV-2 induce the formation of long-lived plasma cells in the bone marrow.

The bone marrow is an important site for immunological memory. It is home to antibody-producing plasma cells that maintain antibody levels in the blood, e.g. for immune protection against pathogens. From previous publications it was already known that this also applies to plasma cells that produce SARS-CoV-2-specific antibodies and have been induced as a result of vaccination or infection.

16 human bone marrow samples were analysed at the DRFZ, some of which were obtained more than a year after the last COVID-19 mRNA vaccination. The researchers found that mRNA vaccination against SARS-CoV-2 induced a specific type of plasma cells whose properties indicated that the cells have a particularly long lifespan compared to other plasma cells. These CD19-negative plasma cells have already been investigated in detail at the DRFZ before. The results from this study highlight that plasma cells continuously produce SARS-CoV-2-specific antibodies following repeated mRNA vaccination, which can reduce the risk of severe COVID-19 disease. Furthermore, the results support that mRNA vaccination can generate potent immune memory and confer long-lasting immune protection.