COVID-19: Why infected people get sick at different rates
The effects of COVID-19, caused by the SARS-CoV-2 coronavirus, vary in severity. Many people do not even notice that they are infected. Others only get sick easily. However, there are also serious illnesses and deaths. Researchers are now reporting new findings on the different courses of the disease.
Scientists have gained new insights into why many people who contract the SARS-CoV-2 coronavirus only contract COVID-19 mildly. Their results were published in the journal “Nature Communications” released.
- Most people’s immune system can contain the spread of the coronavirus in the body so effectively that pneumonia does not develop.
- Exactly how the intruder’s confinement in the upper airway happens, however, has remained largely a mystery.
- Researchers have now found that in patients who are only mildly ill, a specific antiviral upregulation of so-called interferon-stimulated genes takes place.
Successful defense against SARS-CoV-2
Like the LMU Klinikum Munich in a recent Message explains, according to current knowledge, 90 percent of those infected are able to successfully defend themselves against SARS-CoV-2, so that a severe course of the disease with an infection of the lungs is prevented.
In order to find out why this is so, researchers at the LMU Klinikum led by Dr. medical Kami Pekayvaz, Alexander Leuning, PD Dr. medical Konstantin Stark and Dr. medical Leo Nicolai has now examined blood samples and nasal swabs from over 100 patients in cooperation with other research institutions.
This is done using various methods to study genes, proteins and other molecules that play a role in an immune response. The knowledge gained was combined with available clinical data.
The focus of the study was the examination of patient samples over the entire course of the disease. The researchers first closely examined a cohort of corona infected people with risk factors for a severe course and differentiated between those affected with and without lung involvement.
The knowledge gained in this way was then confirmed in a large cohort of outpatients with mild courses.
Very strong antiviral response
According to the authors from the Medical Clinic and Policlinic I of the LMU Klinikum in Munich, they found that early on in the disease, patients “who have shown little or no symptoms have a very strong antiviral response in the immune cells in the blood demonstrate”.
The response is characterized by so-called “ISGs” (interferon-stimulated genes). “These can be imagined as a whole armory of proteins that cells can use against viral invaders,” the experts continue to explain.
They “believe that this type of immune response prevents further spread of the virus because it puts the body on alert and, for example, the lung tissue is prepared for the invader.”
Killer cells appear to be less damaging to cells
In addition, the so-called natural killer cells and T cells appear to be less damaging to cells in milder diseases. This probably prevents damage to the body’s own cells. Finally, there is an anti-inflammatory monocyte signature.
The bottom line is that the scientists say that they have found a “specific immunological signature” that can prevent the spread of SARS-CoV-2 in the body. The immune response is initially independent of antibodies, since these can only be produced as the disease progresses.
According to her, one goal would now be to get the immune system of patients at risk “or of individuals after viral exposure to activate these antiviral mechanisms”.
And: “There are already approaches here, for example nasal sprays were used that trigger such a response via interferon-alpha or other mechanisms”. These approaches must now be optimized.
It would also be promising that such strategies could possibly also help in the next pandemic against viral pathogens other than the SARS-CoV-2 coronavirus. (ad)
Author and source information
This text corresponds to the specifications of medical specialist literature, medical guidelines and current studies and has been checked by medical professionals.
Swell:
- LMU Klinikum Munich: Immunological signature against SARS-CoV-2, (accessed: 07.03.2022), LMU Clinic Munich
- Kami Pekayvaz, Alexander Leunig, Rainer Kaiser, Markus Joppich, Sophia Brambs, Aleksandar Janjic, Oliver Popp, Daniel Nixdorf, Valeria Fumagalli, Nora Schmidt, Vivien Polewka, Afra Anjum, Viktoria Knottenberg, Luke Eivers, Lucas E. Wange, Christoph Gold, Marieluise Kirchner, Maximilian Muenchhoff, Johannes C. Hellmuth, Clemens Scherer, Raquel Rubio-Acero, Tabea Eser, Flora Deák, Kerstin Puchinger, Niklas Kuhl, Andreas Linder, Kathrin Saar, Lukas Tomas, Christian Schulz, Andreas Wieser, Wolfgang Enard, Inge Kroidl, Christof Geldmacher, Michael von Bergwelt-Baildon, Oliver T. Keppler, Mathias Munschauer, Matteo Iannacone, Ralf Zimmer, Philipp Mertins, Norbert Hubner, Michael Hoelscher, Steffen Massberg, Konstantin Stark & Leo Nicolai: Protective immune trajectories in early viral containment of non-pneumonic SARS-CoV-2 infection; in: Nature Communications, (published: 02/23/2022), Nature Communications
Important NOTE:
This article contains general advice only and should not be used for self-diagnosis or treatment. He can not substitute a visit at the doctor.