Atypical B Cells Play a Central Role in COVID-19 Vaccine Response

Vaccines function by strengthening defenses against viruses that invade human bodies. Vaccination against COVID-19 teaches the human immune system's specialized B cells how to identify the virus. These B cells will promptly produce antibodies to fight and destroy the virus if subsequently contract COVID, but because the COVID-19 mRNA vaccines are so novel, the precise B cells that were activated remained unknown to researchers.

Now, in a study published in Nature Communications, a team of researchers from Osaka University has pinpointed the B cells responsible for boosting COVID-19 immunity after vaccination.

Several different types of B cells can be activated after vaccination, but it was not clear which B cells responded to the COVID-19 mRNA vaccine, we found that blood from people who were vaccinated against COVID-19 contained activated atypical B cells. These B cells are the main responders to the vaccine because they are highly correlated with the serum antibody response against the COVID-19 virus.”

David Priest, Study Lead Author, Osaka University

Within the two known groupings of B cells, the scientists examined and identified individual cells using a technique known as mass cytometry. Classical B cells, which are prevalent in human blood, and non-classical B cells are these two types of B cells. The activated atypical cells that were recently found belong to the non-classical group. The investigators also discovered these cells in the blood of COVID-19-infected patients.

Activated atypical B cells provide a new way to assess how well people respond to COVID-19 vaccination. They also give us a new understanding of the underlying biology of mRNA vaccination. Now that we know these B cells are the primary responders to mRNA vaccines, we can work toward targeting them in future vaccine designs.”

James Wing, Study Senior Author, Osaka University

With the assistance of this study, researchers may be able to create better candidate vaccines and updates for the COVID-19 vaccine to help avert future pandemics.