Opinion | Why Are So Many More Men Dying from Coronavirus? – The New York Times

“. . .  What lies behind this female genetic superiority? It starts at the chromosomal level.

To review the typical basic chromosomal differences between the sexes: The cells of genetic females have two X chromosomes — one from their mothers, and one from their fathers — while those of genetic males have only the one X chromosome, from their mothers, and one Y chromosome.

This is crucial, because X chromosomes come in handy for vital functions like building and maintaining the human brain and the immune system. And biologists have long understood that XX chromosomes give females an advantage in some arenas: Having the use of a spare X in case the other is somehow defective is why females are less susceptible to disorders like color blindness, for instance.

But we’re only just now beginning to understand the full advantage that this extra X chromosome confers: It’s not just that women have a spare X chromosome to swap in. Rather, the more than 2,000 genes that, combined, make up two X chromosomes, are used by cells that actually interact and cooperate within a woman’s body. Each cell predominantly uses one X chromosome over the other — so if one X chromosome has genes that are better at recognizing invading viruses like Covid-19, for instance, immune cells using that X can focus on that task, while immune cells using the other X chromosome focus on, say, killing cells infected with Covid-19 instead, making the fight against the virus more efficient.

Typical males, by contrast, are forced to get by in life with just the one X chromosome. What if a male’s particular genes aren’t able to competently recognize or kill off cells infected with a coronavirus? In that case, his ability to fight the infection will be limited; his solitary X is the only one he’s got.

The bottom line is when it comes to dealing with the trauma and stressors of life — whether it’s avoiding a serious congenital malformation, a developmental disability, or fighting off an infection — females have genetic options. And genetic males don’t.”