Though it’s not yet clear why, women around the world have proved to be less likely to get seriously sick with the novel coronavirus — and far more likely to survive it than men. The difference in some contexts is stark: Dr. Sara Ghandehari, a pulmonologist and intensive-care physician at Cedars-Sinai in Los Angeles, told the New York Times that 75% of the hospital’s ICU and ventilator patients are men.
Though there are some rare and scary exceptions, pregnant women especially — though usually immunocompromised and therefore thought to be higher-risk — tend to get very mild cases of the coronavirus. Scientists have some theories they hope might support these differences in outcome by sex, but no one is sure of anything just yet.
Could hormones be responsible?
Because pregnant women have high levels of estrogen and progesterone, and women in general have higher levels of these hormones than men, scientists wonder if the hormones themselves may be protective. If so, could the same hormones then be used to treat COVID-19 in men?
Doctors in New York and Los Angeles have begun trials to evaluate this theory, testing the use of estrogen or progesterone in boosting patients’ immunity.
… Or maybe something other than hormones is responsible.
Experts who study sex differences in immunity caution that hormones may not provide the miracle drug we’re hoping for, citing the better health outcomes even among elderly women, who have far lower levels of estrogen and progesterone after menopause. It’s possible that genetics play a role, and while some sex differences in immunity are biological, some are thought to be behavioral, as well — men smoke more and wash their hands less across the world.
When will we know more?
Preliminary results from the studies in Los Angeles and New York are expected within a few months. Because the association between sex hormones and the immune system is well researched, some doctors remain hopeful about their use in treating COVID-19. Both estrogen and progesterone are believed to be safe when used for short periods of time, though men taking them for the first time may experience breast tenderness and hot flashes.
