That the COVID-19 disease treats men and women differentially is clear.
The first thing that came to light is that fewer women died from COVID-19 than men. Now it is seen that more women than men suffer from “Persistent covid”, a condition in which symptoms last up to 10 months, and can become disabling.
Here we analyze the existing information and possible explanations for both effects.
More deaths from COVID-19 in men than in women
During these months of pandemic, different studies have been carried out on the effect of COVID-19, not only by gender but also by age.
Age it is one of the main risk factors, as observed since the beginning of the pandemic. It is mainly due to a already worn immunity and a higher prevalence of chronic diseases in the elderly population.
The other factor of heterogeneity in mortality due to covid-19 that has been derived from these studies is the gender, where there are significant differences based on sex, with men having a higher risk compared to women.
This could have to do with sex hormones, which seem to be key to adapting the body’s immune response.
But also the presence of other risk factors such as diabetes, hypertension or cardiovascular diseases, which affect men more.
Men, do they have the chance to lose to COVID-19?
In August of last year it was published in the magazine The Lancet a study on the effect of COVID-19 both by gender and by age in different countries such as England, Wales, France, Germany, the Netherlands, Portugal, Korea and Spain.
The following figure shows the mortality ratio between men and women by age range.
It is observed that, from the age of 15, men haveclearly those to lose.
In a study carried out using data in all European countries, this trend is corroborated.
Figure 2 shows the case fatality rate in men over 60 years of age compared to women in Europe. Values below the diagonal indicate that the fatality rate of men is higher than the average for all countries, with the exception of Cyprus and Slovakia.
Different immune response in men and women
After extensively investigating whether differences in immune response against the virus may be behind these data, several groups have reached important conclusions.
First of all, we must know far above how the immune response against a virus works. exist two types of response, the innate and the adaptive.
The immune response innate It is our first line of defense, it would be equivalent to the border guard, as we see in figure 3. It is a type of non-specific response that we share with much less developed living beings, even plants.
Many attempts of infections are eliminated directly with this type of defense. If not enough, cells of the innate immune system “sound the alarm” and go to the immune system adaptive, which would be the equivalent of the army.
In other words, a much more sophisticated system, specific to a pathogen and capable of saving memory of it for the future.
The 3 key facts
Well, three pieces of information have been observed that can explain the differences between men and women in the face of covid-19:
- The SARS-CoV-2 virus has a surprising ability to go unnoticed for the innate immune system and sneak into highly vulnerable areas of the body before the “alarm goes off.”
- The adaptive immune system of men ages much faster than that of women.
- Women have a adaptive immune system very robust (many of whose genes are housed on the X chromosome).
Indeed, when the immune response to COVID-19 is studied in detail in women compared to men, it is observed that the adaptive response in women is more complete.
While in men, especially from 65 years of age, the innate is more powerful, in many cases getting out of hand in the form of the so-called “cytokine storm” that can end the patient in the ICU and cause death.
All this would explain the excess of deaths in men that we have described in the previous point.
Persistent Covid-19: more frequent in women than in men
Persistent covid-19 appears when one or more symptoms of the disease persist over time, between 4 weeks and 10 months after you have overcome the infection. Up to 80% of people have one or more symptoms persistently.
Symptoms that persist over time are chronic fatigue (more than 60%), headache (45%), joint pain, lack of concentration, difficulty in falling asleep, and even anxiety and depression. These are the most prominent in incidence among the more than 50 different symptoms described.
Being a multisystemic disease, persistence involves different organs and affects different functions, so its approach and therapy must be covered by several medical specialties.
According to a study from the United Kingdom, persistent COVID-19 occurs more frequently in women than in men and does not always correlate with severe illness.
Another study recently published in Nature Medicine found that in women under 60 years of age, COVID-19 symptoms are twice as likely to persist for more than a month.
Dividing by age, this proportion is conserved in the 40-50 age segment, but increases to 8 times more in the age segment. 50-60 years. This pattern coincides with that of the prevalence of autoimmune diseases, so it is not excluded that it is related to the immune response to the virus.
In the same direction, a third study from a US group finds that 70% of people with persistent COVID-19 are women.
However, in a recent scientific review that includes several studies on the complex affectation and symptoms of persistent COVID-19, the data for men and women are not disaggregated.
We are again faced with the urgent need to present disaggregated data if we want to avoid biases that may underestimate or dilute information necessary to obtain valid conclusions.
Everything points to the fact that, for clinical purposes of covid-19, women are not so rosy as it seemed at the beginning of the pandemic.
The exposed results accentuate the need to take into account whether it is a man or a woman when diagnosing and treating all kinds of diseases, not only gynecological ones. Hopefully this change in mindset will become a positive and persistent aftermath of the pandemic.
*This article was published on The Conversation and reproduced here under the Creative Commons license. You can read the original version by clicking here.
Matilde Cañelles López is inresearcher cscientific in the Research Group of Science Technology and Society of the Institute of Philosophy (IFS-CSIC), in Spain.
María Mercedes Jiménez Sarmiento is Systems biochemist of the bacterial division and scientific communicator. Nuria Eugenia Campillo is a tenured scientist specializing in medicinal chemistry. Both work at the Margarita Salas Biological Research Center (CIB – CSIC).
Now you can receive notifications from BBC Mundo. Download the new version of our app and activate them so you don’t miss out on our best content.
If you like the information we shared in this article, please like, follow, share and subscribe us on Facebook, Twitter, Tumblr and Instagram so that we can share more such useful articles with you in future.