I could venture a guess. The most recent data released by the CDC ended on October 23rd, 2022, as reported by the Epoch Times.
The CDC has the data, but is sitting on it. My educated guess is that greater numbers of serious side effects have been reported, and the agency doesn’t want the public to hear about it until after everyone has received the latest booster. Not that too many would even care about such a report, but an inconvenient report would certainly take the wind out of future booster sales, and the CDC, being the irreversibly corrupt agency that it is, cares more about vax uptake than it does the well-being of the naive human lab rats who are rolling up their sleeves.
Ideologues, fanatics, and the truly evil have filled our regulatory agencies right under our noses. The EPA, the CDC, AMA, et cetera ad infinitum. These people aren’t merely evil, they exhibit a total indifference to the well-being of those who they hold power over. This is probably a far worse development than if we were dealing with the truly evil. What we have is akin to a teenager plowing mowing down pedestrians in a crosswalk because they cared more about the screen in their hands than they do the safety of others. Evil through indifference.