Until now, we didn’t know all the cogs behind the loss of smell caused by covid. But in May, a study supervised by the Institut Pasteur found that the virus could penetrate far, and even very far into our noses, to our brains.

“The olfactory neurons are a gateway for the virus, to the central nervous system, and to the brain. And so what we think is that the virus enters the olfactory neurons, and then attaches itself to it. along the neurons of the olfactory nerve to reach the brain, this is what has been shown in this study “ explains Prof. Emmanuel Flamand-Roze, neurologist at the Pitié-Salpêtrière hospital in Paris.

The virus enters the olfactory neurons

In our nostrils, the virus first removes the olfactory cilia, which are the odor receptors that surround us. Then the virus infects neurons, travels up the nerve and reaches the olfactory bulb. The whole system is out of order and the infection can last for several weeks.

And this study goes further, since it suggests a link between infection through the nose and neurological damage in the event of Covid, such as memory or concentration disorders. “

If we consider that the gateway to the brain, for the virus, is the nose, at that time, if we treat the persistence of the virus in the nose, we can imagine that we will not only improve odor disorders, but also, perhaps, to improve or limit the neurological disorders which sometimes persist ” adds the professor.

The study thus sheds light on why PCR swab tests can actually miss the virus, lodged far too far in our noses.