Coronavirus covid-19 infects men as well as women. Still, it takes far more men than women to hospital care and to the grave.

In Germany, as many as two-thirds of the deaths are men, in Spain 65% and in China 64%. The same phenomenon has been observed in France, Iran and South Korea. In Italy, men who are hospitalized with covid-19 are 75% more likely to die than women.

Researchers have several explanations for the mismatch. The main causes are biological. Bad life - smoking and drinking - is only on the sidelines.

Smoking is, of course, a risk factor for coronavirus, and in China men are clearly more prevalent than women. Almost half of Chinese men smoke, but only two percent of women. Smoking damages the lungs and causes chronic lung disease and may partly explain the high mortality in men.

- However, the situation is not at all clear in European populations. In some places, women may burn more than men, says Marcus Altfeld, director of the German Heinrich-Pette Institute's Department of Viral Immunology, to Der Spiegel.

According to Altfeld, there are also gender differences in other infectious diseases: influenza, HIV / AIDS and hepatitis. So it's not just about covid-19.

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We thought for a long time that another woman's x-chromosome was not active.

The biological differences between men and women are now being addressed.

- There are two biological factors that are very significant. On the one hand, estrogen and testosterone hormones have an effect, and on the other hand, there are differences between women having two x chromosomes, men only having one, Altfeld says.

Estrogen in women boosts the body's immune system, while male testosterone has the opposite effect, suppressing the immune response. The explanation is in interferon, which regulates the production of proteins that are important in the fight against viruses.

- Research shows that estrogen increases the production of interferons. In a respiratory infection, women are helped by a better ability to produce interferons that prevent the spread of viruses and lung damage, said Susan Kovats, a US immunologist with Xinhua News Agency.

Women have two x chromosomes, each of which, according to a German study, is involved in regulating the immune response.

Photo: Darryl Leja / National Human Genome Research Institute / NIH

In turn, many immune response regulating proteins are directly linked to the x-chromosome.

- We thought for a long time that another female chromosome was not active. But now we know that a woman's immune cells can read the instructions on both x-chromosomes. Therefore, many molecules important for the regulation of immune defense function more strongly in women than in men.

This could also explain the popular phenomenon of "male flu". Women cope with colds and flu better than men, and their response to vaccinations is also better than men.

Samples of covid-19 patients studied in China show that women have more immune-related cells than men.

Immune defenses, which are more capable of female men, are believed to be evolutionary causes. A woman's body is built to protect two people during pregnancy and breastfeeding: the mother and the baby.

The other side of the medal is that women are more likely than men to have so-called autoimmune diseases, including rheumatism. They are diseases in which the immune system attacks the human body.