NEW YORK (VINnews) — Scientists have been pondering why in all countries affected by COVID-19, the mortality rate of men is significantly higher than that of women. In Italy, 70% of those who die from the virus are men, in China 64% and in all the other countries there is an average difference of at least 10% between the mortality rates of males and females.

“When we look at the data what we’re seeing is that in every country with sex-disaggregated data … there is between a 10 percent and 90 percent higher rate of mortality amongst people diagnosed with Covid-19 if they are men compared to if they are women,” Sarah Hawkes, professor of global public health at University College London (UCL), who is also a co-director at Global Health 50/50, which has analysed Covid-19 mortality deaths by sex across the world, told

Scientists maintain that unhealthy lifestyles and addictions such as smoking and drinking could be responsible for male susceptibility to the virus.

In most cases, the coronavirus has affected lungs, inflating them to the point that patients gasp for oxygen as they struggle to breathe, which in most cases leads to one or multiple organ failures, accelerating the chances of death. Since smokers and drinkers have less healthy lungs, their chances to fight off the virus with or without life support are less.

Worldwide data from 2015 have shown that men smoke and drink almost five times more than women, according to CNN.

However there are other genetic factors which could also explain this phenomenon. Women’s strong immunity system responds to viral infections much sooner and stronger, and this is directly related to estrogen and female fertility.

“Every pregnancy makes the female body rejuvenate. In order to feed her baby, the female body produces various hormones in high levels. Those hormones also renew their tissues and cells. As a result, they have such a natural advantage [in terms of surviving],” Mehmet Yildirim, a general surgery specialist and a professor of medicine at the Bilecik University, told TRT World.

Women also have two X chromosomes, which makes them capable of fighting back various diseases, since the X chromosome contains genes which improve the immune systems ability to identify pathogens and destroy them, as opposed to males who only have one X chromosome and whose high testosterone may actually weaken their immune system.

“Why does estrogen protect the woman, and how? We’d like to know,” Stanley Perlman, a pediatric infectious disease specialist at the University of Iowa, told the Los Angeles Times. Perlman is one of the rare scientists who studied coronavirus infection in mice between 2016 and 2017, finding out that male mice are more susceptible to the virus than females.

The scientist also discovered that the mortality rate of female mice went up if their ovaries were taken out or their estrogen activity was prevented.

As a result, beyond old age or smoking, the real reason behind the high mortality rate of men from Covid-19 might be a weak immune system that finds it hard to repel deadly viruses with the same efficiency as female bodies do.

Scientists also believe that the female body’s initial strong reaction to the virus attack is one of the key weapons enabling it to fend off infection. Experts say that if the first reaction fails to stop the virus, the latter responses of the immune system might create more problems than addressing the issue, increasing the levels of infection in the lungs.

“When [a] severe outcome is caused by an inability to rapidly control the infection, then it is often adult males who suffer worse outcomes than females,”  Sabra Klein, a professor at Johns Hopkins’s Bloomberg School of Public Health told The Washington Post.