A 33-year-old woman developed paresthesia in her right thumb approximately 30 minutes after receiving the BNT162b2 (Pfizer-BioNTech) severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine. The paresthesia gradually spread to her right-side limbs and trunk, and cervical magnetic resonance imaging (MRI) revealed a localized lesion in the right dorsal column. After glucocorticoid therapy, her symptoms and MRI findings improved. Although disease developing less than 24 h after vaccination is considered an unlikely cause of immuno-associated adverse events following vaccination, we discuss the possible mechanisms involved in early-onset central nervous system inflammation after vaccination in view of preexisting immunopathological susceptibility.