From infertility to risk of death – how coronavirus is hitting men harder

As a study finds Covid may impact male fertility, we explore the reasons why men are affected by the virus more than women

Men are being affected more than women by coronavirus

Although we’re fast approaching the first anniversary of Covid being declared an official pandemic by the World Health Organisation, there is still so much about the virus and its effects that remain unknown. 

One such effect is the virus’s impact on fertility. A study published last month from Justus-Liebig-University in Germany suggests that a case of Covid may have a significant negative impact on male fertility. It compared men who had been hospitalised with Covid against age-matched healthy men. It found that in those with Covid, inflammation and oxidative stress in sperm cells were increased by more than 100 per cent, pathways that facilitate sperm cell death were activated, sperm concentration and mobility was reduced, and sperm cell shape was altered by 400 per cent. 

Beyond the question of fertility, the study follows several others that have found that while the virus can infect anyone, men are still more likely to become unwell and die from Covid compared with women of the same age. One study from Yale University last summer found that women mount stronger immune responses to fight pathogens, which the researchers believe is due to their bodies being designed as such to protect unborn children during pregnancy. 

Another study published in April 2020 found that while men and women were equally likely to catch Covid, men were more likely to suffer from severe effects of the virus. Research from China found that over 70 per cent of those who died from the virus were men. In Europe, WHO research found that 63 per cent of deaths related to Covid were in men, while another study in Italy found that among those who were hospitalised 8 per cent of men died compared with 5 per cent of women. 

So why do men seem more susceptible to the worst of the virus’s effects? A recent study in the European Heart Journal found that men tend to have higher concentrations of ACE2 receptors in their blood. ACE2 receptors are what allow Sars-CoV-19 to access and infect cells, so it stands to reason having more of them increases the risk factor. We also know that having a Y-chromosome leads to a weakened immune system compared with those with two X-chromosomes as women do, which is why men have been observed to have a weaker immune response to seasonal flu viruses than women. 

There are also lifestyle conditions to account for. Men are statistically more likely to smoke, for example. “Smoking may be associated with more severe coronavirus symptoms and a higher risk of dying,” explains Dr Luke Powles, associate clinical director at BUPA Health Clinics. “Smoking can also mean you touch your mouth more, which may increase your risk of catching the virus.” 

Powles also cites research that shows men tend to drink more alcohol than women, which is bad for the immune system and has been linked with other illnesses that affect the lungs (though not specifically coronavirus). Finally, “Some research has found that men may be less worried about coronavirus than women,” adds Powles. “This might mean they don’t follow guidelines as strictly or don’t seek medical help as quickly as they should.”

On the subject of fertility, based on his research and expertise, Jonathan Ramsay, a consultant urologist and male fertility expert at Lister Fertility Clinic, sees no reason for men who have been affected by Covid to be overly worried. 

“We know that these were severely ill men [in the study] and we know that being severely ill has negative effects on fertility,” says Ramsay. “The bigger question is whether the majority of young men who don’t get sick have an independent effect on fertility.” 

It has already been observed that severe illnesses, particularly those that cause fever, can cause a drop in fertility. “It makes sense biologically,” explains Ramsay, “that if a man is ill it might not be a good time for him to procreate.” In these cases, the effect is usually transient and the man’s fertility will recover within six months. 

It might also be unfair to compare men hospitalised with Covid with those who haven’t been, as the very conditions which can increase the risk factor for Covid hospitalisation – age, weight, and pre-existing conditions – also have a negative effect on fertility. In addition to that, the anti-viral drugs and corticosteroids used to treat severe cases of Covid may also temporarily impact fertility. “The more important question with a virus that is pandemic, is whether it has a specific and parallel effect irrespective of illness or treatment,” says Ramsay. 

Because normally fertile men don’t tend to get their sperm tested and certainly wouldn’t have done so routinely before being diagnosed with Covid, it’s also difficult to form a complete picture of the exact effect of Covid before and after infection. 

However there are some biological reasons that could provide a hypothesis to link reduced fertility with Covid. We know, for example, that Sars-CoV-2, which causes Covid, attaches to ACE2 receptors, which appear on many cell types around the body such as the lungs, heart, and blood vessels. Pertinently ACE2 receptors are also involved in smelling pheromones and are found in the testicles. On a purely theoretical level, Ramsay concedes that this might explain a link between the anosmia symptoms of Covid and a loss in fertility, although he’s careful to explain that such a link is far from having been proved. 

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