OAS1 gene, Spike protein variants and persistent COVID-19-related anosmia: May the olfactory disfunction be a harbinger of future neurodegenerative disease?

It is currently known that anosmia is a sign of SARS-CoV2 infection, as well as the symptom is caused by the neuroinflammation of the olfactory bulbs. To date, it is unknown why some patients suffer from persistent anosmia. The suspect is that genetic of the host can be responsible of this persistent symptom. Moreover, also spike variants can have a role in the symptom persistence. The susceptibility to the neuro-inflammation in the olfactory bulbs might be similar in the whole brain predisposing these patients to future neurodegenerative disease neuro-inflammation related. A precocious treatment might be helpful to avoid long neurologic sequela.