Do vaccines cause guillain-barre syndrome (gbs)?

No link. No, there is no definitive link between vaccines and gbs in a broad sense. While many have attempted to link the two and the fda follows all vaccines closely to monitor a link - the data has not suggested a link between all major vaccines and gbs. The average risk of someone getting gbs even without getting vaccines is 1 in a few hundred thousand. The risk is the same with vaccines.
Associated. Gbs has been associated with vaccination but the cause is unknown.