Pfizer published the vaccine “package insert” when the vaccine was approved by the FDA. Prior to full approval, when the vaccine was merely authorized for emergency use, the vaccine “package insert” was left intentionally blank. Vaccine manufacturers don’t have to publish information in the vaccine insert until FDA approves the vaccine.
It is interesting to note, that we other side effects, such as “Antibody Dependent Enhancement (ADE)” was also a known risk, as called out during the FDA’s advisory committee (VRBPAC) meeting on December 10, 2020:
This has been affirmed in the following article published in March 2021: