Immune Imprinting



    • 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