More memory B cells exist in those fully vaccinated with previous SARS-
CoV-2 infection, study says

Date:
October 4, 2021
Source:
University of Minnesota Medical School
Summary:
A new study shows differences in immune responses among those
vaccinated, including the amount of memory B cells and their
vaccine binding performance.



FULL STORY ==========================================================================
A new study by University of Minnesota Medical School researchers is
revealing that some people who received an mRNA vaccination for COVID-19
have greater immune responses compared to others. While the vaccine
induces strong immune responses against the virus in almost everyone,
data shows those who were previously infected with the virus have even
greater immune responses after vaccination compared to fully vaccinated
people who never had COVID-19.


==========================================================================
Marc Jenkins, PhD, a professor and director of the Center for Immunology
at the University of Minnesota Medical School, is the corresponding
author, and Kathryn Pape, PhD, is the first author of a study published
in Cell Reports.

Jenkins and Pape are renowned experts on B cells, the immune cells in
the body responsible for producing antibodies.

"Memory B cells are capable of rapid antibody production after
re-infection, which is critical for immunity as antibody levels decline," Jenkins said. "Our research shows that fully vaccinated people who had a
prior SARS-CoV- 2 infection end up with an even larger number of memory
B cells than fully vaccinated people who have not had an infection."
The study found that:
* People with a previous SARS-CoV-2 infection had a large number
of spike-
specific memory B cells before vaccination, and after the first
dose of an mRNA vaccine, had a significant boost in spike-specific
memory B cells -- but not after the second dose;
* Despite the weaker response to the second mRNA dose, people with a
previous SARS-CoV-2 infection still ended up with a larger number
of spike-specific memory B cells than fully vaccinated people who
never had the virus, and;
* The spike-specific memory B cells in people with a previous
SARS-CoV-
2 infection bound more tightly to the spike protein of the virus
compared to the memory B cells induced in uninfected people after
a single mRNA vaccination.

"Our results show the benefit that people who had a SARS-CoV-2
infection get from vaccination and predict that this group may have
fewer breakthrough infections," Jenkins said. "While it's unclear how
many memory B cells are needed for protection against infection, our
data also indicates that people who had a previous infection and were
then fully vaccinated are the least likely group to need a third -- or
booster -- shot." This team is now studying memory B cell formation in
fully vaccinated people with immunosuppressed systems.

The study was funded by the Office of the Dean at the University of
Minnesota Medical School.

========================================================================== Story Source: Materials provided by
University_of_Minnesota_Medical_School. Original written by Angel
Mendez. Note: Content may be edited for style and length.


========================================================================== Journal Reference:
1. Kathryn A. Pape, Thamotharampillai Dileepan, Amanda J. Kabage, Daria
Kozysa, Rodolfo Batres, Clayton Evert, Michael Matson, Sharon
Lopez, Peter D. Krueger, Carolyn Graiziger, Byron P. Vaughn,
Eugenia Shmidt, Joshua Rhein, Timothy W. Schacker, Alexander
Khoruts, Marc K. Jenkins.

High affinity memory B cells induced by SARS-CoV-2 infection
produce more plasmablasts and atypical memory B cells than
those primed by mRNA vaccines. Cell Reports, 2021; 109823 DOI:
10.1016/j.celrep.2021.109823 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2021/10/211004104112.htm

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