Aseptic Meningitis Following Second Dose of an mRNA Coronavirus Disease 2019 Vaccine in a Healthy Male: Case Report and Literature Review

Vaccines are one of the most important strategies against pandemics or epidemics involving infectious diseases. With the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), there have been global efforts for rapid development of coronavirus disease 2019 (COVID-19) vaccine and vaccination is being performed globally on a massive scale. With rapid increase in vaccination, rare adverse events have been reported. Well-known neurological adverse events associated with COVID-19 vaccination include Guillain–Barré syndrome, myelitis, and encephalitis. However, COVID-19 vaccine-related aseptic meningitis has rarely been reported. A 32-year-old healthy man visited our hospital with a complaint of headache for 1 week. He had received the second dose of the BNT162b2 mRNA COVID-19 vaccine 2 weeks before the onset of headache. Since the initial cerebrospinal fluid (CSF) profile suggested viral meningitis, we started treatment with an antiviral agent. However, the symptoms and follow-up CSF profile on day 7 of hospitalization showed no improvement and SARS-CoV-2 IgG antibodies were detected in the CSF. We suspected aseptic meningitis associated with the vaccination and intravenous methylprednisolone (500 mg/day) was administered for 3 days. The symptoms improved and the patient was discharged on day 12 of hospitalization.