Immune Imprinting

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.

Source: IE