COVID-19 Vaccine Priority for People With Neurologic and Rare Diseases

The pandemic illness caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has led to the identification of numerous common neurologic complications, which may result directly or indirectly from infection [1]. The most well-known neurologic symptom is anosmia/dysgeusia (loss of sense of smell/taste) [2] whose uniqueness to SARS-CoV-2 has been debated [3]; involvement of skeletal muscles is also very common and fortunately mild in most cases (predominantly myalgias), although myositis and rhabdomyolysis are described [4, 5]. Rarely, more significant neurologic complications arise [6]. In the central nervous system, some of the described phenotypes include encephalopathy [7], neuroimmunological syndromes [8], and myoclonus/ataxia [9]. Ischemic stroke appears to have a more severe outcome in COVID-19 patients but was not more common in a recent large series [10]. Peripheral nervous system complications mainly relate to above-mentioned complications of skeletal muscle, as well as variants of Guillain-Barré syndrome [11-13]. Mononeuritis multiplex has been described with high prevalence in a series of critically ill patients with COVID-19 [14], which is a group of patients in whom neurologic impairments may be difficult to identify and may be misattributed to critical illness neuro/ myopathy. When present, neurologic syndromes have been associated with increased mortality in COVID-19 patients [15]. SARS-CoV-2 infects cells via angiotensin-converting enzyme 2 (ACE2), a protein found abundantly among numerous cell types including neurones of the central and peripheral nervous systems, and muscle [16-18]. Therefore, neurologic complications may occur as a direct consequence of viral infection, in addition to neurologic damage resulting from hypoxia, the inflammatory cascade, and other end-organ injuries. As a result, there is concern that patients with pre-existing neurological disorders may be at greater risk of neurological complications, or more severe outcomes in general from COVID-19 [19].