When Immunity Falls Short: Meningoencephalitis Despite Vaccination - A Case Report

Varicella-zoster virus (VZV) significantly impacts the central and peripheral nervous systems, particularly in immunocompromised individuals. This case report details a rare presentation of VZV meningoencephalitis in a 42-year-old woman with interstitial lung disease and connective tissue disease undergoing lung transplant evaluation who presented with a thunderclap headache and a new-onset seizure. Despite normal initial MRI findings, further investigation with PCR of the cerebrospinal fluid (CSF) revealed the presence of VZV, indicating VZV meningoencephalitis. The patient had been immunosuppressed with prednisone, sulfasalazine, hydroxychloroquine, and mycophenolate and had received a 2 dose series of recombinant zoster vaccine (Glaxosmithkline, Brentford, England, UK) seven months prior to presentation. Initial diagnostic considerations included reversible cerebral vasoconstriction syndrome, but a lack of response to nimodipine and abnormal CSF findings shifted the diagnosis towards VZV meningoencephalitis. The patient was treated with intravenous acyclovir, which led to initial improvement. However, she developed bilateral lower extremity weakness after discharge, with MRI showing multifocal nodular leptomeningeal enhancement. Subsequent tests ruled out coccidioidomycosis and suggested ongoing VZV infection. After extensive antiviral treatment with valaciclovir, the patient's condition stabilized, and she ultimately successfully underwent a lung transplant without complications. This case of VZV meningoencephalitis underscores the need for heightened clinical suspicion, vigilance, and prompt intervention in high-risk populations to prevent severe outcomes.