Men also tend to engage more in unhealthy behaviors, like smoking or drinking alcohol, and they are more reluctant to seek medical care, all of which can lead to worse outcomes when they do fall ill.
But studies in animals and humans show that there are biological differences, as well, when it comes to the male and female immune systems.
“Women often produce or mount greater immune responses,” regardless of what the illness is, said Sabra Klein, a professor of molecular microbiology and immunology at Johns Hopkins University.
Differences between the sexes emerge even before an infection takes hold. Females’ immune cells are faster at detecting foreign invaders, like viruses or bacteria. When a threat is identified, the female immune system releases more inflammatory proteins, called cytokines. It also produces more antibodies in response to both viruses and vaccines, which help to fight off an infection.
Of course, there are individual differences, but women “tend to initiate those types of responses much more rapidly, and we get greater activation and greater production” of immune proteins, Dr Klein said.
WHAT EXPLAINS THESE DIFFERENCES?
Genetics are thought to play an important role. Several genes that are involved in the immune system are on the X chromosome, and as you may remember from high school biology, females have two X chromosomes while males have one.
As a result, the function of those genes, like detecting viruses or producing cytokines, is slightly heightened in females during an infection, said Montserrat Anguera, an associate professor of biomedical sciences at the University of Pennsylvania School of Veterinary Medicine, who specialises in the topic.
Sex hormones likely factor in, too. Testosterone appears to dampen some aspects of immune functioning, like antibody production, while oestrogen enhances it, though oestrogen has also been shown to suppress the immune system’s inflammatory response.
