Postvaccinal Encephalitis after ChAdOx1 nCov-19

Abstract

The global SARS-CoV-2 pandemic has contributed to more than 163 million confirmed infections and 3.3 million deaths worldwide. The severity of the pandemic has led to an unprecedented effort to develop multiple effective vaccines. Due to excellent safety and efficacy data from clinical trials, several vaccines were approved. We report a case series of postvaccinal encephalitis in temporal correlation to vaccination with ChAdOx1 nCov-19. The diagnostic criteria for possible autoimmune encephalitis were fulfilled. Our patients responded well to immunosuppressive therapy with corticosteroids. The incidence has been estimated to be approximately 8 per 10 million vaccine doses. Complication of postvaccinal encephalitis after ChAdOx1 nCoV-19 vaccination still appear to be very rare, but need to be diagnosed and treated adequately. Large pooled data from observational epidemiologic studies are necessary to verify causality. ANN NEUROL 2021;90:506-511.

FIGURE 1

First Patient 1A‐D, Second Patient 2A‐D, Third Patient 3A‐D (1A to 3A): Representative electroencephalographic recordings from all three patients using A‐P (anterior‐posterior) longitudinal bipolar montage (sensitivity 7 mcV/mm; filter 1 to 70 Hz; interval between 2 vertical lines: 0.3 seconds). (1B to 3B): Representative images of CSF cytology demonstrating lymphocytic dominance. (1C‐D to 3 C‐D): Representative T2w (2C‐D) and FLAIR MR Images (1C‐D, 3C‐D) on admission (C) aswell as at 2‐4 months follow‐up (D). Zoomed views were chosen according to the very clinical symptoms described, e.g. showing normal appearance of the fastigial nucleus (arrows in 2C‐D). No imaging evidence of acute disseminated encephalomyelitis (ADEM) was depicted. [Color figure can be viewed at www.annalsofneurology.org]