There is enough data now to know who, statistically speaking, is at greater risk for severe illness and death from COVID-19, the illness caused by the coronavirus dubbed SARS-CoV-2. But it’s not always clear why certain people are more susceptible.
Those who have chronic illnesses, such as diabetes, high blood pressure, or heart disease, are likelier to get more severe cases. Older people are more prone to serious cases, and are at greater risk of dying. African-Americans are getting sicker and dying more frequently from COVID-19 than other ethnic groups.
And, around the world, men are getting sicker and dying more often than women.
For most of the above groups, researchers have solid theories to make sense of the disparities. People who have chronic illnesses already have compromised health. The older people get, the more likely they are to have such chronic illnesses. And African-Americans are more likely to suffer from heart disease, high blood pressure, and diabetes than other groups.
But why the great disparity between men and women?
There are a few hypotheses. The first is that men, overall, lead less healthy lifestyles than women, and especially, that they tend to smoke more.
A paper in The Lancet, however, dispelled the notion that smoking was a big factor. While 50 percent of Chinese men smoke, in two studies analyzing COVID-19 deaths in China, much lower percentages of those men who died from COVID-19 were smokers—between 1.4 percent and 12.6 percent. Further, according to the authors of an as-yet unpublished study of more than 4,000 cases in New York City “[W]e did not find smoking status to be associated with increased risk of hospitalization or critical illness.”
So, smoking can’t account for the differences in severity between the sexes.
Another hypothesis points to the fact that men tend to be less healthy, overall, than women. While it’s true that men have higher rates of diabetes and higher blood pressure, in another Wuhan study, men were almost twice as likely to die of the illness—a full 72.9 percent of those who died were male. That’s a much greater difference in death rates than in the incidences of these underlying illnesses. So, while overall relative health could be a factor, it can’t account for the vast majority of the difference. Something else has to be going on.
That something else might involve the immune system—but, if so, it’s not clear why.
It’s true that women have more robust immune systems, which can work to either their advantage or detriment. Because a woman’s immune system is more attuned to beating back any perceived foreign invader, it is also more likely to get into full battle gear when there’s nothing foreign invading, instead, going full Rambo on its own body’s cells, sometimes with disastrous results; 80 percent of auto-immune disease cases occur in women.
Still, when it comes to infectious disease, that hyper-vigilant immune system can be an advantage.
During the SARS outbreak in Hong Kong in 2003, although more women were diagnosed with the disease, a greater percentage of men who got it died. Infectious diseases, overall, are usually more deadly for men. (An exception to that rule, the Black Death killed more women than men in 14th to 15th century Europe).
However, in cases of the coronavirus, it isn’t infection, per se, that’s causing the vast majority if severe illness. Instead, it’s the immune system, itself, that’s killing so many of us. So, the fact that men succumb to infectious disease at a higher rate shouldn’t be a factor.
What appears to cause COVID-19’s most deadly effects, whether in men or women, is a combination of two flawed immune responses. The first flaw: the immune system is slow to respond. It should be pumping out killer cells from the get-go, but the spigot that normally opens wide to do that is, in effect, rusted almost shut. That allows the virus to invade cells with impunity.
Then, belatedly, the immune system awakens. Once it gets the message to attack, it hits that rusty immune cell spigot with the equivalent of a sledgehammer, knocking it clear off the pipe.
Proteins called cytokines pour out and overwhelm the lungs and sometimes other organs—an extreme version of what happens with out-of-control auto-immune disease reactions. Once this “cytokine storm” gets going, it sometimes doesn’t stop until the patient is dead.
If this is happening more often in men than women—because more men are experiencing severe cases and death—it raises the question of why? Why does a man’s usually lazier immune system suddenly rev to the point where it leaves the woman’s more vigilant immune system in the dust?
With COVID-19, there are a multitude of unproven conjectures: which animal played intermediary between bat and human; how many cases of the disease the US actually has; what medications can best treat it; and even how much immunity people who have recovered will have in the future. The question of why men are more at risk of severe disease or death than women is one more question for which we lack definitive answers.