Some Patients Never Regain Their Sense of Smell After COVID Infection, and Researchers Finally Understand Why

Some Patients Never Regain Their Sense of Smell After COVID Infection, and Researchers Finally Understand Why

It is possible for COVID-19 (the disease caused by the coronavirus) to cause loss of smell or taste. This symptom, known as anosmia, is more common in people with severe cases of COVID-19, but it can also occur in people with mild or asymptomatic cases of the disease. Anosmia is thought to be caused by inflammation or damage to the olfactory nerve, which is responsible for carrying information about smells from the nose to the brain.

It’s important to note that loss of smell or taste can also be caused by a number of other factors, such as nasal congestion, allergies, sinus infections, and head injuries. If you are experiencing a loss of smell or taste, it is important to speak with a healthcare provider to determine the cause and receive appropriate treatment. In the case of COVID-19, anosmia is typically a temporary symptom that improves as the body recovers from the infection.

But unfortunately, it’s not always temporary, which is indeed a bummer. 

T cells are destroying nerve cells of COVID patients

A new study that The Jerusalem Post tells the world about reveals that scientists can finally explain why some people who got COVID never recover their sense of smell: their immune system is destroying too many olfactory nerve cells. More specifically, the T cells are to blame.

T cells (also known as T lymphocytes) are a type of white blood cell that plays a key role in the immune system. They are produced in the bone marrow and mature in the thymus, which is why they are called T cells. There are two main types of T cells: CD4+ T cells and CD8+ T cells.

In order to investigate olfactory epithelial samples, including those from COVID-19 patients suffering from long-term anosmia, the researchers employed a biopsy-based approach.

The scientists discovered that the T cells appear to be reacting in an autoimmune-like manner in the nose, with inflammation present in the olfactory epithelium where the nerve cells for smell are located.

The study in question belongs to scientists led by Bradley Goldstein from Duke University, while experts from Harvard University and the University of California San Diego were also included.

The new findings were published in the peer-reviewed academic journal Science Translational Medicine.


Even since he was a child, Cristian was staring curiously at the stars, wondering about the Universe and our place in it. Today he's seeing his dream come true by writing about the latest news in astronomy. Cristian is also glad to be covering health and other science topics, having significant experience in writing about such fields.

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