Jeremy R. Hammond
Studies have now confirmed that “original antigenic sin”, or a detrimental fixation on a suboptimal immune response, is a real problem for people who’ve gotten COVID-19 vaccines.
In brief, what can happen is that an initial viral infection or vaccination can result in an individual’s immune system becoming fixated on generating responses to the original antigen even during subsequent infection with different strains characterized by different epitopes, or molecular structures capable of being recognized and responded to by the immune system. Thus, the immune response to a new strain can result in an inferior immune response in immunologically experienced people relative to the immune response induced by the new strain in immunologically naïve individuals.
Other terms that are sometimes used to describe this phenomenon include “viral interference”, “immune interference”, “antigenic fixation”, and “immune imprinting”.