Women and men’s immune systems work differently. So what does this mean for gender differences when it comes to disease treatments or vaccine dosing?
Our immune system is incredibly complex and incredibly fascinating. Our bodies produce about 100 billion immune cells every day. Our lymph nodes are located in our blood, spleen, liver, and intestines. They protect us from bacteria, viruses, fungi, environmental toxins, and other pathogens. But how does this complex interplay of defenders work? And why do women have a genetic advantage when it comes to immune defense?
Whether or not male colds actually exist has not been scientifically proven. In fact, on average, men have a less powerful immune system than women. This is largely due to genes, or more precisely, chromosome combinations. Most genes that affect the immune system are located only on the X chromosome.
So people with two X chromosomes generally have a more resilient defense mechanism than those with an X and a Y chromosome. “Women are more resistant to infections,” says Bodo Grimbacher of the Center for Chronic Immunodeficiency at the University Hospital Freiburg.
more Autoimmune disease
But there is a downside to having a double dose of immune genes. “Women are more prone to autoimmune diseases,” says Grimbacher. That’s why women suffer more from autoimmune diseases like Hashimoto’s, lupus, and multiple sclerosis.
These diseases are associated with a malfunction in the immune system, which causes the immune system to attack its own cells, nerves, tissues, and ultimately organs. “Systemic lupus is nine times more common in women than in men,” says Bodo Grimbacher, who treats autoimmune diseases in Freiburg.
Testosterone suppresses the immune system
However, it is not only genes that determine our body’s defense functions, but also sex hormones that affect our immune system. The female hormones estrogen and progesterone can promote the formation of specific antibodies of the acquired immune system. On the other hand, the male hormone testosterone tends to suppress the activity of the immune system and can even partially suppress the immune response.
Another factor that has not been studied extensively is the hormonal changes during the menstrual cycle and how this affects the immune response during this phase. However, it is common for women’s immune system function to decline after menopause due to hormonal changes.
But as we age, our immune systems become less effective. But what do these gender differences mean for disease treatments and vaccine dosing?
Gender Medicine Epidemic?
Each individual’s individual characteristics and chromosomal combination determine their susceptibility to infections. However, the different ways in which the immune systems of men and women react have so far been little considered in clinical practice, at least according to Markus Kornberg, director of the Center for Individual Infection Medicine in Hanover.
Men are generally more susceptible to chronic infections, such as hepatitis B, while women more frequently react to infections or adverse reactions to vaccines. “In the hospital, we see chronic viral infections much more often in men than in women,” said Cornberg, who has studied hepatitis for years.
Women have experienced side effects from COVID-19 vaccines more than twice as often as men during the pandemic. At the same time, antibody titers have shown that women have better protection against the vaccine after vaccination.
“As a scientist, I ask myself, can we give women a lower dose of the vaccine to reduce side effects, or, conversely, can we give men a higher dose to increase their resistance?” says Cornberg. For drugs used to treat infections, dosages often vary by age. But there are clear differences in the degree of effectiveness, but they are rarely gender-specific.
Biological and social sex
Until now, most of the research in science has been about men and women. It is often unclear what the research team actually understands as ‘man’ and ‘woman’. Here, the research refers to biological sex, that is, the distribution of chromosomes, sex hormones, and primary and secondary sex characteristics. Social gender, which also includes non-binary people, is distinct from biological sex. In this article, the terms ‘man’ and ‘woman’ are also used as biological sex.
However, regardless of gender, respiratory infections are just as common in cold and rainy weather as they are in general. Our bodies work incredibly hard to fight them off. A 73kg man’s immune system consists of about 1.8 trillion cells, weighing 1.2kg. A 60kg woman has about 1.5 trillion immune cells, weighing about 1kg. This means that the human body uses about 5% of its total cells for defense. It’s an incredible feat.
