Extended SARS-CoV-2 RBD booster vaccination induces humoral and cellular immune tolerance in mice
"Highlights
• Extended immunizations impaired the serum neutralization activity
• Extended immunizations suppressed the formation of germinal center
• Extended immunizations inhibited the activation of CD8+T cells
SUMMARY
The repetitive applications of vaccine boosters have been brought up in face of
continuous emergence of SARS-CoV-2 variants with neutralization escape muta-
tions, but their protective efficacy and potential adverse effects remain largely
unknown. Here, we compared the humoral and cellular immune responses of an
extended course of recombinant receptor binding domain (RBD) vaccine
boosters with those from conventional immunization strategy in a Balb/c mice
model. Multiple vaccine boosters after the conventional vaccination course signif-
icantly decreased RBD-specific antibody titers and serum neutralizing efficacy
against the Delta and Omicron variants, and profoundly impaired CD4 + and
CD8 + T cell activation and increased PD-1 and LAG-3 expressions in these
T cells. Mechanistically, we confirmed that extended vaccination with RBD
boosters overturned the protective immune memories by promoting adaptive
immune tolerance. Our findings demonstrate potential risks with the continuous
use of SARS-CoV-2 vaccine boosters, providing immediate implications for the
global COVID-19 vaccination enhancement strategies."
You are getting allergy shots for the virus spike protein.
What happens when you build tolerance to the virus? You get very sick for a long time when you get infected. The vaccine is doing the opposite of your expectations.
https://www.sciencedirect.com/science/article/pii/S2589004222017515