Encephalitis following COVID-19 Vaccination: A Systematic Review

Abstract

Background: Since the advent of global COVID-19 vaccination, several studies reported cases of encephalitis with its various subtypes following COVID-19 vaccinations. In this regard, we conducted a systematic review to investigate and characterize the clinical settings of these reported cases to aid in physician awareness and proper care provision. Methods: We systematically searched PubMed, Web of Science, and Scopus and manually searched Google Scholar. Studies published until October 2022 were included. Demographic data, clinical features, vaccine data, treatment lines, and outcomes were extracted. Results: A total of 65 patients from 52 studies were included. The mean age of patients was 46.82 ± 19.25 years, 36 cases (55.4%) were males. AstraZeneca was the most-reported vaccine associated with encephalitis (38.5%) followed by Pfizer (33.8%), Moderna (16.9%), and others. Moat encephalitis cases occurred after the first dose of vaccination in 41/65 (66.1%). The mean time between vaccination and symptom onset was 9.97 ± 7.16 days. Corticosteroids (86.2 %) and immunosuppressants (81.5 %) were the most used lines of treatment. The majority of affected individuals experienced a full recovery. Conclusion: Our study summarizes the current evidence of reported post-vaccination encephalitis, regarding clinical presentation, symptoms onset, management, outcomes, and comorbid conditions; however, it fails to either acknowledge the incidence of occurrence or establish a causal relationship between various COVID-19 vaccines and encephalitis.

Central nervous system immune-related disorders after SARS-CoV-2 vaccination: a multicenter study

“…the occurrence after the first or, less frequently, the second dose in most of the patients, as previously described ( 17 , 19 , 42 ) and, again, in line with the mechanistic hypothesis of these disorders;…”

“…(7-11 days) ( 16 ), Abdelhady et al. (9.97 days) ( 42 ), Jarius et al. (13 days) ( 36 ), Asioli et al.…”

Association of New-Onset Seizures With SARS-CoV-2 Vaccines

“…Indeed, seizures could be caused by induction of glutamate release and inhibition of the release of inhibitory neurotransmitters, triggered by proinflammatory cytokines in the brain, as also happens in SARS-CoV-2 infection . Furthermore, SARS-CoV-2 vaccines could result in autoimmune encephalopathy, which is commonly associated with seizures …”

Immunopathogenesis of viral infections in neurological autoimmune disease

“…They showed that covid-19 vaccine can induce acute transverse myelitis, MS, acute demyelinating encephalomyelitis (ADEM), and neuromyelitis optica spectrum disorder (NMOSD) [ 152 ]. Moreover, Abdelhady et al reported 65 patients who developed encephalitis following covid-19 vaccines [ 153 ]. Despite first presentation of MS after covid-19 vaccine was reported in some studies [ 154 – 157 ], Stefanou et al showed that Covid-19 vaccination is not associated with increasing the risk of relapse of patients with MS irrespective to the type of covid-19 vaccines [ 158 ], and therefore, most of the patients with MS are willing to receive covie-19 vaccine [ 159 ].…”