Review Article
Volume 14 Issue 6 - 2022
A SARS-COV-2 Entry Pathway Shift for the Omicron Variant Might Explain a Less Severe Disease
Calixto Machado-Curbelo1*, Joel Gugierrez-Gil1 and Alina González-Quevedo2
1Department of Clinical Neurophysiology, Institute of Neurology and Neurosurgery, Havana, Cuba
2Department of Neurobiology, Institute of Neurology and Neurosurgery, Havana, Cuba
*Corresponding Author: Calixto Machado-Curbelo, Department of Clinical Neurophysiology, Institute of Neurology and Neurosurgery, Havana, Cuba.
Received: February 28, 2022; Published: May 27, 2022


The Omicron variant led to exponential increases in cases and a sharp rise in hospital admissions. The wave increased faster than previous waves, completely displacing the Delta variant within weeks, creating worldwide worries about the final pandemic control. Omicron is the fifth variant to be named as a variant of concern (VOC) by the World Health Organisation (WHO) and the third (after Alpha and Delta) to achieve global dominance. Although Omicron is fast-moving, several initial reports suggest a less severe disease. Some authors have emphasized that the symptoms associated with Omicron have differed from these "traditional" symptoms and are closer to the common cold. It is also curious that one major COVID-19 symptom rare-the loss of taste and smell. Dr. Machado has suggested that one of the main causes to explain ARDS refractory to treatments is the direct invasion of SARS-CoV-2 to the brainstem from the olfactory nerves through transsynaptic pathways. SARS-CoV-2 infection of the brainstem can deeply damage the respiratory center, triggering functional deviations that affect involuntary respiration leading to ARDS refractory to treatments, which is the main cause of death in Covid-19 patients. A shift in the Omicron SARS-CoV-2 entry pathway from cell surface fusion, triggered by TMPRSS2, to cathepsin-dependent fusion within the endosome, may impact transmission, cellular tropism, and pathogenesis. Therefore, we can hypothesize that this entrance modification may impact transmission from the olfactory nerve to the brainstem through transsynaptic pathways. Hence, a decrement of the virus's direct invasion to the brainstem would diminish respiratory center dysfunction, with less possibility of an ARDS complication and the need for mechanical ventilation in ICUs.


Keywords: Covid-19; SARS-CoV-2; Omicron Variant; Acute Respiratory Distress Syndrome (ARDS); Entry Route


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Citation: Calixto Machado-Curbelo., et al. “A SARS-COV-2 Entry Pathway Shift for the Omicron Variant Might Explain a Less Severe Disease”. EC Neurology 14.6 (2022): 14-20.

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