Neurological complications of COVID-19 and SARS-CoV-2 vaccination: an update

The respiratory infectious disease COVID-19, which emerged in 2019, has affected the world population over a brief period. In 2020, the disease was declared a pandemic by the World Health Organization. Although most COVID-19 patients primarily develop respiratory symptoms, neurological symptoms have been observed. Neurological symptoms are usually mild and non-specific. However, some patients could experience life-threatening neurological symptoms. With the increase in the incidence of COVID-19, the disease spectrum of patients with central and peripheral nervous system involvement has expanded significantly compared to the previous period. Lack of awareness has caused delays in diagnosis and treatment; therefore, updating the disease spectrum of neurological complications of COVID-19 is necessary. After COVID-19 claimed millions of lives, researchers found that some vaccines may induce autoimmune inflammatory responses in the nervous system via molecular mimicry, leading to SARS-CoV-2 vaccine-related neurological deficits. These neurological complications are often ignored by clinicians, delaying diagnosis and treatment; it is essential to study cases of vaccine-associated neurological complications. Therefore, we summarize the neurological complications of COVID-19 and nervous system adverse reactions caused by SARS-CoV-2 vaccines to help clinicians and public health service personnel understand these rare complications. Avoiding delays in diagnosis and treatment would ensure the safety of COVID-19 patients and SARS-CoV-2 vaccine recipients.