Partly because it is a bad career move for 'medical professionals' to produce data which 'causes vaccine hesitancy'. Bogus data gets framed in misleading ways (as you are doing here.) Also, one can die from getting 'bitten by a cow' because there is a medical code for it unlike being killed by the experimental gene therapy injection.
medical codes forr covid vaccine reactions etc. much more can easily be found.
IOW no one is hiding things that can happen.
https://icd10monitor.com/coding-covid-19-vaccination/Other complications following immunization, not elsewhere classified, initial encounter. In my opinion, there are several situations which warrant this code. Complications directly related to the procedure of immunization, but not related or due to the medication per se, might fit into this code. If a patient sought treatment because the injection was erroneously placed into their deltoid tendon or their shoulder joint, that would be T88.1XXA. A large hematoma or a firm lump from a resolving hematoma…T88.1XX- (7th character of “S” if it were a sequela). They are finding that patients develop localized rashes over the injection site, known as “COVID Arm,” or generalized rashes. These index to T88.1XX-
If a patient presents with a known significant allergy to COVID-19 vaccine, they would have pre-existing Z88.7, Allergy status to serum and vaccine. This might lead to Z28.04, Immunization not carried out because of patient allergy to vaccine or component.
Let’s circle back to the original question, “post vaccination weakness and mental status changes.” The codes I would select for the documentation of this case would be: R53.1, Weakness, R41.82, Altered mental status, unspecified, and T50.B95A, Adverse effect of other viral vaccines, initial encounter.
edit: o_e_l_e_o beat me to it. but ill leave this though.