Scientists from the United States have discovered a new method that allows predicting the severity of the course of coronavirus infection based on tests from the nasopharynx. The study is published in the journal Cell.

Employees of the Boston Children’s Hospital, together with specialists from the Massachusetts Institute of Technology and the University of Mississippi Medical Center, studied nasal swabs taken from 35 patients with coronavirus. According to scientists, tests from the nasopharynx are more effective than studies of blood samples.

The authors of the work found out that epithelial cells in the nose and throat undergo serious changes when infected with SARS-CoV-2. Thus, in patients with mild and moderate degrees of severity of COVID-19, genes responsible for the antiviral response were activated in these cells, especially those that were stimulated by type I interferon.

In people with a severe course of the disease, antiviral reactions, on the contrary, were blunted due to a weak reaction of epithelial cells to interferon. Their smears showed an excess of macrophages and other immune cells that enhance inflammatory reactions.

According to one of the researchers, Jose Ordovas-Montanes, a weakened reaction to interferon, which helps regulate the activity of the immune system, makes people more susceptible to both coronaviruses and other infections.

Now scientists plan to find out the cause of such a reaction, and also to understand whether it can be enhanced by nasal sprays or drops.