GBS indicates Guillain-Barré Syndrome; RZV, recombinant zoster vaccine; ZVL, zoster vaccine live. A, the cohort analyses, blue dots represent individual cases observed following RZV vaccination, and the green dots represent cases observed following ZVL vaccination. B, the self-controlled analyses, the red dots represent individual cases observed following a first dose of RZV, and the grey dots represent cases observed following a second dose of RZV.