Men infected with Sars-CoV-2 are three times more likely than women to be admitted to intensive care, and also more likely to die from it, according to a study which questions the biological differences between the two sexes.
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Since the start of the Covid-19 epidemic, experts have noted a greater number of severe cases in men.
For more specific information, the authors of this study published Wednesday, December 9 in
Nature Communications
analyzed data from 46 countries and 44 states in the United States from January 1 to June 1, or 3.1 million confirmed cases. of Covid-19.
According to these data, there is no difference between men and women for contamination, "
exactly
" half of the confirmed cases being men.
On the other hand, the probability for a sick man to be hospitalized in intensive care is almost three times higher (2.84 times) than for a woman, and the probability of dying is also higher (1.39 times).
This phenomenon is "
global
", with a few exceptions, underlines the study, which explains this situation mainly by biological factors.
Based on other studies already published, the authors suggest that women naturally produce more type 1 interferon, a substance that limits the abnormal immune response ("
the cytokine storm
") pointed out in the forms serious cases of Covid-19.
They also produce more T lymphocytes which kill infected cells.
The presence in women of the "
female
"
hormone
estradiol would also offer greater protection against infection.
On the contrary, testosterone would limit the immune response in men, the study says.
Beyond this “
real biological difference
”, the authors also evoke the possibility that the presence of more significant comorbidities in men comes into play.
But they point to the lack of data that can be used to assess the role of these additional factors.
However, they note that there is no major difference between the two sexes at the global level for two comorbidities increasing the risk of severe forms of Covid: hypertension and diabetes.
Even if other studies are necessary, "
these data have implications for the clinical management of Covid-19
", estimates the study.
"
These data could help doctors realize that sex is a real risk factor for severe forms when caring for patients,
" said Dr Kate Webb of the University of Cape Town in South Africa, referring to also a possible implication for vaccines.
“
Other vaccines (...) have shown different responses depending on the sexes.
Whether this will be the case with the Sars-CoV-2 vaccine remains to be seen, but we hope our study highlights the need to include gender as a variable in vaccine research
, ”she added.