The reason women fought better with Covid-19

Men die from Covid-19 higher than women. Photo: Getty Images.
Men die from Covid-19 higher than women. Photo: Getty Images.

Not only with Covid-19, many other mammalian diseases also appeared to be more susceptible and dead than females.

In countries where Covid-19 has experienced strong outbreaks such as the United States, Italy and China, statistics show that the rate of men dying from the disease is higher than that of women. Where is the cause? Do genes, hormones, immune systems or lifestyle habits make men more susceptible to disease?

I see that is the resonance of all the above factors. Not only with SARS-CoV-2 virus, many other mammalian diseases also appear to be more susceptible and dead than males.

Cruel numbers

In Italy and China, the Covid-19 mortality rate for men is twice as high as for women. This figure in New York (USA) is 61%. Australia has a similar pattern, although deaths mostly fall between the ages of 70-79 and 80-89.

A major factor influencing mortality among people with Covid-19 is age. However, this does not explain gender disparities.

The occurrence of chronic diseases – especially heart disease, diabetes and cancer – also puts patients at risk of dying from SARS-CoV-2 virus infection. These diseases are more common in men than women. Therefore, it may affect the rate at which we are concerned.

But the question is, why are men susceptible to these diseases?

Biological differences

Men and women differ in their sex chromosomes and the genes located on them. Women have 2 medium-sized chromosomes (called X). Men have only one X chromosome and the small Y chromosome contains few genes.

One of these Y genes (SRY) drives the embryo to become male by stimulating the development of testes in the embryo containing the XY chromosome. The testes produce a male hormone, causing the child to develop into a boy. In the absence of SRY, the ovaries form and create female hormones.

Hormones control most of the differences between men and women, from the genitals, breasts, hair to body shape, and greatly influence the behavior.

Y chromosomes and hormones

The Y chromosome causes problems for men. Photo: Nature Genetics.
The Y chromosome causes problems for men. Photo: Nature Genetics.

The Y chromosome hardly carries any genes other than SRY but it is filled with repetitive genetic sequences, called junk DNA. There is a possibility that some “toxic medicine” is out of control in the aging process. This speeds up aging in men and makes them more susceptible to viral infections.

But the most serious problem for men is the male hormone produced by SRY. Testosterone levels are associated with many diseases, especially heart disease and affect longevity. At the same time, men are disadvantaged by low estrogen levels, factors that protect women from many diseases, including heart disease.

Male hormones also affect behavior. High levels of testosterone are noted in people who have dangerous actions such as smoking, drinking too much alcohol, not listening to medical instructions and rarely visiting clinics.

Typically the smoking rate in China. Nearly half of men smoke while the rate is only 2% for women. Smoking is not only a factor leading to respiratory diseases, but also causes lung cancer, which makes patients at high risk of death from Covid-19.

The advantage of X chromosomes

Sex chromosomes significantly affect the mortality rate of Covid-19. Photo: Science Alert.
Sex chromosomes significantly affect the mortality rate of Covid-19. Photo: Science Alert.

X chromosomes carry more than 1,000 genes with important functions, including daily metabolism, blood clotting and brain development.

The presence of two X chromosomes in females provides a defense mechanism; if one X gene is mutated, the other will complete the task. Males with an X-set lack a copy of the X chromosome. That’s why boys are more susceptible to sex-related diseases, such as blood clotting.

Children not only have twice the X gene, but also benefit from two different versions of each gene. This is a profound cause for the higher death rates of males than females of any age since birth.

And another man’s problem is the immune system.

Scientists have known for a long time that women have a stronger immune system than men. This is not always good, because it makes them more susceptible to diseases caused by the immune system itself, such as lupus erythematosus and multiple sclerosis. But thanks to this, women are less susceptible to the virus, many studies on mice and people have proved this.

This is also the cause for men being more susceptible to viral infections in previous outbreaks, including SARS and MERS.

Having at least 60 immune genes on each X chromosome. It seems that higher doses and two different versions give women a broad range of defense.

An inevitable part of nature

Differences in the frequency of infection, severity, and effectiveness of treatment in male and female patients have long been noted. Covid-19 is only part of a known model. This is true even for most mammals.

It is thought that male mammals transmit their genes by winning sexual partnerships, so the hormone that controls dangerous behavior is a natural advantage. In the opposite direction, female mammals develop traits that enhance the ability to take care of the offspring, thus making the immune system stronger.

Thus, the gender disparity in Covid-19 deaths can be seen as part of a large and well-known picture. Main differences in genes, chromosomes and hormones lead to different responses between males and females for diseases.