The timing of the pandemic has put the common cold and seasonal allergies mixing with the coronavirus in our daily life.
Our noses are loading influenza, coronavirus and pollens every day.
Viral load is the amount of viruses in the body.
A patient’s viral load increases as the virus replicates and disease symptoms get worse.
The amount of virus that we are exposed to at the beginning of an infection is very important.
The more viruses we breathe in, the greater our chances of having more severe infections.
With one small exposure, the immune system may be able to fight off the virus before we get sick.
But with repeated small exposures or one large exposure, the virus may grow faster than the body can fight.
So reducing the viral load at the initial site can protect us from catching infection.
The coronavirus spreads through the airway.
About 85% of COVID-19 patients had loss of smell.
The loss of smell suggests the possibility of direct targeting by the coronavirus in the nose.
Indeed, a new study found a main entrance of the coronavirus inside the nose.
The coronavirus sneaks into humans cells through a key receptor—ACE2.
Using the spike-like protein on its surface, the coronavirus binds to ACE2.
As a key is inserted into a lock, a coronavirus has to find an ACE2 lock to get into a human cell.
Hence, ACE2 acts as a cellular lock in the human body for the coronavirus.
A study found a hot spot of ACE2 lock deep inside the nose.
This hot spot is the area that detects smells.
In this regions, levels of ACE2 were between 200 and 700 times higher than other parts of the nose and trachea.
Detection of COVID-19 in clinical samples showed that the highest viral copy number was found in nasal swabs (~200 fold), compared to throat swabs.
In the early stages of COVID-19 infection, viral genetic material can readily detected in the nose but not in blood, urine, or stool.
These data suggest that active virus infection and replications occurs in the nose.
The lower ACE2 lock in the nose of children relative to adults may explain the lower prevalence of COVID-19 children.
Mengfei Chen et al. Elevated ACE2 expression in the olfactory neuroepithelium: implications for anosmia and upper respiratory SARS-CoV-2 entry and replication, European Respiratory Journal, 2020
Rinsing the nose with salt water can reduce viral loads.
This is a powerful tool to decrease the risk of coronavirus infection,
because salt is toxic for most of the respiratory viruses.
Salt water creates a chemical called hypochlorous acid, which is the same chemical inside bleaches with antiviral effect.
Rinsing the nose is as important as washing our hands in preventing the coronavirus.
It could be months before a coronavirus vaccine is available.
We should beat the COVID-19 before a vaccine is ready.
An ounce of prevention is worth a pound of treatment.
