booster was never tested on humans, only mice: https://www.nbcnews.com/health/health-news/fda-authorize-new-covid-boosters-data-tests-people-rcna45387
booster supposedly "updated" but just as ineffective against new variants, as the old shots: https://www.biorxiv.org/content/10.1101/2022.10.22.513349v1.full.pdf
FDA panel approved it anyway; panel members now claim to be "disappointed" and "angry" over vaxx companies withholding relevant data: https://www.cnn.com/2023/01/11/health/moderna-bivalent-transparency/index.html
that CNN article mainly hits Moderna, but Pfizer won't escape, as you'll see.
boosted individuals dying suddenly - it's all over twitter - mainly focused on "excess death" statistics & younger athletes with cardiac events -
but if you want something different - media report of "preliminary" data tying Pfizer's booster to strokes in elderly: https://www.bloomberg.com/news/articles/2023-01-13/pfizer-bivalent-vaccine-linked-to-stroke-in-preliminary-data
P.S. This all known awhile. The real story here is that CNN, Bloomberg, NBC, FDA would say it.
Big Pharma "owns" them - in the sense of supplying huge ad revenues & 65% of FDA budget.
That they're complaining & reporting these things is significant, even weird.