Why women may fair better with COVID-19

Jun 29, 2020

At least since the time of Shakespeare, men have used the phrase “the fair (or fairer) sex” to refer to women. This is greatly ironic, given that men have been all too willing to treat women unfairly from ancient times to the present. Women are also sometimes characterized – by men, of course – as being the more delicate or weaker sex. But the truth is that women are stronger than men when it comes to fighting off diseases like COVID-19. Additionally, females of all mammal species are better at coping with stress than their male counterparts.

How women are stronger

We know that testosterone makes it easier for males to be physically stronger than females. This is believed to be an adaptation selected through evolution which enables males to protect females – who are more essential than men in terms of species survival – as well as any babies in their care. Among humans I find it heartbreaking that while nature (or God, if you like) designed men to safeguard women, too many men corrupt the intended order of things by committing violence against women. 

When it comes to living through pandemics, however, women are two times as strong as men. According to an April 18, 2020 article in the British newspaper The Guardian, twice as many men as women have died from Covid-19 in Spain. The Guardian also recounts that in Italy, the case fatality rate is 10.6% for men and 6.0% for women, and that early data from China revealed a death rate of 2.8% among males compared to 1.7% for females. Even after correcting for lifestyle influences like the fact that more men than women smoke, the disparity is still significant.

It’s true that in some places, Québec for example, women have perished at a higher rate. This may be a demographics issue. The Montréal Gazette reports 80% of Québec health-care workers are female, and women comprise 85% of those in nursing homes, which have been especially hard-hit by COVID-19. Regardless of Québec’s exception and a few others, Global Health 50/50, an institute which tracks worldwide cases, states that the clear trend globally is that more men are succumbing. 

In his book The Better Half (published in 2020, but written before the COVID-19 outbreak), physician Sharon Moalem explains that the majority of genes which regulate the immune system are located on the X chromosome. As we learned in basic Biology class, men have an XY chromosome pair while women have an XX complement. This means women have twice as many X chromosomes in every cell in their bodies, and according to Dr. Moalem, potentially two times the immune response.

How COVID-19 infects a cell

Credit Vega Asensio / Creative Commons

I won’t get into the mechanics (mainly because I barely understand them) of how the COVID-19 virus “unlocks” a receptor protein called ACE-2, thereby obtaining carte blanche to run amok in our bodies. The important point is that the ACE-2 protein is dependent on a set of genes located on the human X-chromosome.

Dr. Moalem says that when the virus circumvents this protein in a male, the virus is then free to infect any cell of any organ in his body. With females, the virus needs to hack into two separate ACE-2 proteins related to two different X chromosomes, giving the female immune system a backup or “second chance” to defend her body from infection.

Coping with stress

It has long been known that female lab rats and mice recover from a stress event more readily than males, which maintain elevated cortisol levels and other markers for stress much longer after whatever traumas are visited upon them in the course of various tests. But in the human realm, a study done at the University of California at Los Angeles in 2000 found that women handle chronic stress better than guys do. 

In the final report, principal author Shelley E. Taylor writes that while the male “fight or fight” response is well-documented (until recently, 80% of all stress research was done on males), females have an additional and (at that time) lesser-known reaction pathway. Calling it a “tend and befriend” response, Dr. Taylor says that women’s proclivity to create and maintain social bonds helps them weather difficulties better than men.

"Oxytocin, in conjunction with female reproductive hormones and endogenous opioid peptide mechanisms, may be at its [the ‘tend and befriend’ response] core,” she said.

Since the time of Dr. Taylor’s study, this female tend-and-befriend phenomenon has been further researched and validated, notably by Lauren A. McCarthy of Rochester Institute of Technology. It looks like the fair sex has some pretty fair benefits when it comes to surviving pandemics and other adversities.