Immune Imprinting

January 27, 2023

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Context

Recent studies find ‘immune imprinting’ might be making bivalent boosters less effective.
- The bivalent booster is the most recent version of the vaccine that develops better immunity against coronavirus.

Immune Imprinting

It is a tendency of the body to repeat its immune response based on the first variant it encountered through infection or vaccination.
Imprinting acts as a database for the immune system, helping it put up a better response to repeat infections.
The concept was first observed in 1947.

Issues with with Immune Imprinting

After our body is exposed to a virus for the first time, it produces memory B cells that circulate in the bloodstream and quickly produce antibodies.
When a similar or variant of virus enters the body, the immune system, rather than generating new B cells, activates memory B cells, which in turn produce antibodies that bind to features found in both the old and new strains, known as cross-reactive antibodies.
Although these cross-reactive antibodies do offer some protection against the new strain, they aren’t as effective as the ones produced by the B cells when the body first came across the original virus.

Adaptive Immune System

Adaptive immune responses are carried out by white blood cells called lymphocytes.
There are two broad classes of such responses—antibody responses and cell-mediated immune responses, and they are carried out by different classes of lymphocytes, called B cells and T cells, respectively.
B cells mature in the bone marrow (hence the name “B cell”).
Cells that eventually become T cells travel from the bone marrow to the thymus by way of our bloodstream where they mature (hence the name “T cell”).
The thymus is located just above the heart behind the sternum, or breastbone.

Source: IE