1.  Immune imprinting is a phenomenon whereby initial exposure to one virus strain limits the development of immunity against new minor variant strains of the virus.  

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2.  Researchers are largely in agreement if boosters are given in a very short period of time after the initial primary series, without allowing a resting period, there’s probably little benefit in having a booster shot for people who are not immunocompromised.

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3.  Repeatedly updating SARS-CoV-2 vaccines may not be fully effective because of limitations imposed by prior immune imprinting to ancestral SARS-CoV-2 strains.

4.  SARs-CoV-2 is a new virus and few humans have yet been exposed to more than one SARs-CoV-2 or vaccine strain.  It is possible that serial exposure to several related strains over time might be required to most effectively “imprint” memory B cell immune responses to ancestral SARS-CoV-2 strains and, consequently, limit neutralizing antibody responses to new strains.
 

5.  Imprinting may come directly from an acute infection or indirectly through vaccination. It can result in reduced — or enhanced — responses to future variants with unknown clinical consequences. The former is beneficial, but the latter is not.

6.  It is hoped that immune imprinting will not be a major problem for SARS-CoV-2 infections, but the possibility that immune imprinting can substantially reduce the efficacy of future SARS-CoV-2 vaccines requires further research at this time.
 

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8440232/

https://www.science.org/doi/10.1126/science.abm0811

https://www.medicalnewstoday.com/articles/what-immune-imprinting-means-for-the-future-of-covid-19-vaccines#Vaccines-of-the-future