How long would Guillain–Barré syndrome take to show up in someone after an injection?

Guillain-Barré syndrome is rare. Usually Guillain-Barré occurs a few days or weeks after a person has had symptoms of a respiratory or gastrointestinal viral infection. Occasionally, surgery or vaccinations (any vaccinations) will trigger the syndrome. It can develop over the course of hours or days, or it may take up to 3 to 4 weeks. Most people, however, recover from even the most severe cases of Guillain-Barré syndrome, although some continue to have some degree of weakness.