Rare cases of Guillain-Barré syndrome after COVID-19 vaccination, Germany, December 2020 to August 2021

The impact of COVID-19 on autoimmune diseases

Various autoantibodies, such as antinuclear antibodies (ANA), anti-Ro/SSA, rheumatoid factor, lupus anticoagulant, and antibodies against interferon type I (IFN-I), have been frequently detected in COVID-19 patients, indicating a significant prevalence of autoimmune reactions following viral exposure. Additionally, the identification of human proteins with structural similarities to SARS-CoV-2 peptides as potential autoantigens underscores the complex interplay between the virus and the immune system in triggering autoimmunity. The chapter discusses probable pathways contributing to COVID-19-related autoimmunity, including bystander activation due to hyperinflammatory states, viral persistence, and the formation of neutrophil extracellular traps. These mechanisms illuminate a spectrum of autoimmune-related symptoms that can manifest, ranging from organ-specific to systemic autoimmune and inflammatory diseases. Importantly, there is emerging evidence of de novo autoimmunity arising after COVID-19 infection or vaccination, where new autoimmune conditions develop in previously healthy individuals. While various COVID-19 vaccines have received emergency use authorization, concerns regarding potential autoimmune side effects persist. Ongoing research is crucial to clarify these relationships and enhance our understanding of the risks associated with COVID-19 infections and vaccinations.

SARS-CoV-2 Vaccination and Neuroimmunological Disease: A Review

Importance

The temporal association between the occurrence of neurological diseases, many autoimmune diseases, and vaccination against SARS-CoV-2 has been topically interesting and remains hotly debated both in the medical literature and the clinic. Given the very low incidences of these events both naturally occurring and in relation to vaccination, it is challenging to determine with certainty whether there is any causative association and most certainly what the pathophysiology of that causation could be.

Observations

Data from international cohorts including millions of vaccinated individuals suggest that there is a probable association between the adenovirus-vectored vaccines and Guillain-Barré syndrome (GBS). Further associations between other SARS-CoV-2 vaccines and GBS or Bell palsy have not been clearly demonstrated in large cohort studies, but the possible rare occurrence of Bell palsy following messenger RNA vaccination is a topic of interest. It is also yet to be clearly demonstrated that any other neurological diseases, such as central nervous system demyelinating disease or myasthenia gravis, have any causative association with vaccination against SARS-CoV-2 using any vaccine type, although it is possible that vaccination may rarely trigger a relapse or worsen symptoms or first presentation in already-diagnosed or susceptible individuals.

Conclusions and Relevance

The associated risk between SARS-CoV-2 vaccination and GBS, and possibly Bell palsy, is slight, and this should not change the recommendation for individuals to be vaccinated. The same advice should be given to those with preexisting neurological autoimmune disease.