Do you have a theory as to what could be causing long covid? i was infected in december and still have fatigue, gi upset, dizziness, tachycardia, paresthesias in a waxing and waning fashion. does the vaccine improve these symptoms? what do we do?

Lots of theories, little “hard facts”. Most likely an ongoing immunologic reaction originally triggered by the presence of the coronavirus but now continuing after the virus is gone. Several similar conditions in Medicine - Reactive Arthritis, “Chronic” Lyme. Very recent report (last week) that vaccine helps. Needs confirmation

Physicians have noticed that many people with the prior infection have lingering problems for months. Many of your issues are not uncommon, especially fatigue, but will gradually resolve in future.. Would get vaccine but would wait for at least 90 days after full resolution of the original infection. Do work closely with your doctor.