See the organism in question. Prior post vaccination GBS is NOT a risk for subsequent GBS (PubMed).
"Infection with cytomegalovirus or Epstein–Barr virus is associated with the demyelinating Guillain– Barré syndrome, whereas C. jejuni infection is associated with the axonal Guillain–Barré syndrome and with the Miller Fisher syndrome (2012 NEJM Review)."
Shingles increases risk 20 x in the next two months (PubMed) as does acute CMV.. The incidence of CMV-GBS is between 0.6 and 2.2 cases per 1000 cases of primary CMV infection versus 0.25 to 0.65 cases per 1000 cases of Campylobacter (PubMed).
Antibiotics are not needed. Plasmapheresis and IVIG are often given for GBS.
Relevant links to my Medscape blog