In early February, the Chinese authorities had been fighting the dangerous coronavirus epidemic for a month, so the Chinese Center for Disease Control and Prevention (CCDC) conducted its first study of patient data.
The investigation included 138 patients of COVID-19 who had been hospitalized, of which the average age was 56 years and 54.3% were men.
Weeks later, they carried out a larger study, with the medical records of 72,314 patients, the data showed a similar result: 51% of the confirmed cases were men.
But what most caught the attention of experts is that the mortality rate also had higher numbers: 2.8% in men versus 1.7% in women.
While another study published in the medical journal Lancet on data from 99 patients infected with the virus showed that the average age was 55.5 years and that they had infected 67 men and 32 women.
However, part of the specialists' conclusion is that coronavirus infection "is more likely to affect older men who already had some other disease" before becoming infected.
But why are men more vulnerable to COVID-19 than women?
Sabra Klein , from the department of molecular microbiology and immunology at the John Hopkins University School of Public Health, explained to the BBC that estrogen (the main group of female hormones) could be the key to different responses to the disease.
"Estrogens can stimulate aspects of immunity that are important to eliminate a viral infection and respond well to vaccines," he said.
With these data, Klein believes that the hypothesis that estrogens contribute significantly to greater immunity in women during the new outbreak could be raised.
But since the epidemic is recent, there is still no research to definitely endorse this.
"Several studies of mice infected with the previous SARS coronavirus outbreak, estrogen definitely contributed to how female mice controlled the infection better than their male counterparts," the expert added.
This also happened with the common influenza virus because, in an analysis performed on cells taken from the lining of the nose of men and women, they found that estrogen greatly reduces the amount of influenza virus that replicates in the cells. infected.
So this made scientists believe in a possible protective effect of estrogen in the fight against viruses.
While, for Dr. Janine Austin Clayton, associate director of research on Women's Health at the National Institute of Health in the United States, this research showed “the importance of studying the cells of men and women, and considering sex as a biological variable when collecting and analyzing data on cells. ”
Women with greater immunity
Women tend to have greater immunity than men after viral infections, including influenza, which could have the female population more prepared for an epidemic such as this.
However, both scientists agree that there are various social and cultural factors are also influencing the death rate of men is higher.
In this sense, Dr. Janine Austin Clayton , explained to the BBC that a large gender difference is the percentage of women and men who go to the doctor when they are sick.
"According to a study by the Centers for Disease Control and Prevention in the United States, American women were 33% more likely than men to see a doctor when they feel bad," he said.
Other factors that are having a direct impact on the mortality of men who contract coronavirus are the existence of previous diseases and age, because Chinese men also show higher rates of type two diabetes and higher blood pressure than women.
Clayton also said that cardiovascular disease is a risk factor "associated with worse outcomes in the current coronavirus outbreak and men may have more heart disease than women in the age ranges in which people die."
However, that women have a stronger immune system also has a drawback.
"Although a greater immune response in women contributes to a faster elimination of microbes, these robust responses can also contribute to a greater susceptibility to inflammatory and autoimmune diseases among women," Clayton concluded.
See also:
Tips to optimize your hygiene and thus prevent the transmission of coronavirus
Why do children under 10 seem to be immune to Coronavirus?