Wai Dai writes over in the comments at Omicron Variant Post #1: We’re F***ed, It’s Never Over:
From your linked paper https://www.cell.com/trends/immunology/fulltext/S1471-4906(21)00177-0: [Wai Dai's quote from the paper in italics]
Experience from the IAV field indicates that multiple serial exposures to variant IAV strains might imprint (focus) the immune response to a narrow array of well-conserved viral epitopes relative to emerging subsequent strains and this might eventually reduce vaccine effectiveness. Randomizing multiple cohorts over time to either serial or partial immunization might also yield important neutralization data, although powering such studies for efficacy would be challenging. Larger observational studies of cohorts receiving serial immunizations might therefore also prove useful.
This suggests that it may be a good idea to avoid getting a booster now (with the ancestral spike protein) and wait for an Omicron-specific booster instead. (Use other precautions to avoid infection in the meantime.)
Given that this is an important question for many of us, I consider it useful to have the conversation on the top level instead of only in the comments of the other thread.