All vaccines have the occasional rare side effect; Guillian-Barré is one of the more well known ones, and people get it from the flu shot each year. It's also quite clear the COVID vaccines haven't killed 600k in the US like the disease has, though. As with any other health intervention, the cost/benefits have to be weighed; they have been continue to be with regards to the vaccines.
EU lists rare nerve disorder as side-effect of J&J COVID-19 vaccine : https://www.reuters.com/business/healthcare-pharmaceuticals/...