A recent peer-reviewed paper appreared in the Journal of Medical Virology where the authors examine the infection routes of the SARS-CoV-2. The researchers points out the fact that signs of viral activity in the brain, where mainly neurons are being infected. Clinical signs of this includes nausea, headache and vomiting, but also the loss of spontaneous breathing due to neurological damage.

The authors hypothesise  that intranasal infection route may increase the risk for severe illness since this route facilitate SARS-CoV-2 neuroinvasion.

If the neuroinvasion of SARS-CoV-2 does take a part in the development of respiratory failure in COVID-19 patients, the precaution with masks will absolutely be the most effective measure to protect against the possible entry of the virus into the CNS. It may also be expected that the symptoms of the patients infected via facal-oral or conjunctival route will be lighter than those infected intranasally.

Clinical implications of include treatment strategies. The use of cortecosteroids may enhance viral replication in the neurons and accelerate the neurological symptoms, while early treatment through inhalation of antiviral agents could inhibit replication in airways and lungs, and subsequent neuroinvasion.