Men are more affected by serious forms of the disease than women. Different immune responses could explain this phenomenon.
Men and women are not equal in the face of Covid-19. Of the people who have died from the disease worldwide, 60% are men. For researchers at Yale University (United States), the explanation for these differences lies in the immune system. “Men and women develop different types of immune response to Covid-19″, explains the lead author of the study, Akiko Iwasaki. Details of the research are published in the journal Nature.
The female immune system is more active
Our immune system relies on white blood cells to fight infections. When they are caused by a virus, it is the T lymphocytes which are activated to eliminate the infected cells. In this new research, scientists found that the action of T cells was stronger in women than in men, in the case of Covid-19. Even older women had high activity of these immune cells. Conversely, the older the men, the weaker their immune response.
Akiko Iwasaki and her team also noticed that men produced more cytokines at the onset of the disease. Other studies have shown that this overproduction is the consequence of an excessive immune reaction, and that it can aggravate the symptoms. Some women were also affected by this overproduction of cytokines, they were systematically affected by more serious forms of the disease.
Differential treatments?
For the researchers, these conclusions suggest that a differentiated treatment of the disease could be more effective. “We should improve the T cell response via vaccines” in men, believes Akiko Iwasaki and “block the cytokine response” in women. However, two limitations to this study should be noted: the research was carried out on a small sample of patients, 17 men and 22 women, and the average age was sixty years, which is high.
Differences studied for several months
Other scientists have looked at gender differences in the epidemic. At the end of March, Inserm researchers explained that lifestyle factors could explain why men were more affected. “In China, men smoke more than women and also have higher rates of type 2 diabetes and high blood pressuredetailed Charles Guéry, at Science and Future. Other factors would be biological, with women developing immune responses of greater amplitude and better quality than men in response to viral infections or vaccines..” This could be linked to estrogen, female sex hormones capable of regulating cells of the immune system.
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