The expedited roll-out of these vaccines has created some public distrust regarding the safety of these new vaccines. This review compiles clinical data from reports of diagnosed immune-related neurological events that have occurred post-COVID-19 vaccine administration except for those secondary to hematological abnormalities. A systematic literature search was performed, using several databases, to identify reports of post-vaccination adverse neurological events. The search resulted in 18 studies that met the criteria. These studies included 78 patients who had received COVID-19 vaccines and experienced at least one neurological adverse effect. The most common neurological event was Facial nerve palsy (62.3% of all events). Other less frequently reported events included the reactivation of herpes zoster, Guillain-Barre Syndrome, other demyelinating diseases, and neuropathy. The underlying mechanism was hypothesized to be related to vaccine-induced type 1 interferon production leading to decreased tolerance of the myelin sheath antigens. Other hypotheses include vaccine-induced transient lymphopenia and immune dysregulation. Most of the reported events were time-limited and resolved spontaneously. Given the rarity of reported neurological events compared to the total number of vaccines administered, and the similarity in the incidence of events between COVID-19 vaccines and other more common vaccines, there is little evidence to support a causal relationship between COVID-19 vaccines and adverse neurological events.
Shafiq A, Salameh MA, Laswi I, Mohammed I, Mhaimeed O, Mhaimeed N, Mhaimeed N, Paul P, Mushannen M, Elshafeey A, Fares A, Holroyd S, Zakaria D. Neurological Immune Related Adverse Events Post-COVID-19 Vaccination: A Systematic Review. J Clin Pharmacol. 2021 Dec 18.
doi: 10.1002/jcph.2017