Contrary to myths circulating on social media, COVID-19 vaccines have been found not to cause erectile dysfunction and male infertility. However, it turns out that SARS-CoV-2, the virus that causes COVID-19, poses a risk for both disorders.

So far, little research has been done on how the virus or vaccines affect the male reproductive system, but recent surveys by doctors and researchers here at the University of Miami have shed new light on these questions.

The team, which understands me, have discovered potentially far-reaching implications for men of all ages, including younger and middle-aged men who wish to have children.

What the team found

I am the director of the Reproductive Urology program at the Miller School of Medicine at the University of Miami. My colleagues and I analyzed autopsy tissue from the testes of six men who died from COVID-19 infection.

The result: the COVID-19 virus appeared in the tissues of one of the men; a decrease in the number of sperm appeared in three.

Another patient – this one a COVID-19 survivor – underwent a testicular biopsy about three months after his initial COVID-19 infection cleared. The biopsy showed the coronavirus was still in his testicles.

Our team has also found that COVID-19 affects the penis. Analysis of penile tissue from two men receiving penile implants showed the virus to be present seven to nine months after their diagnosis of COVID-19. Both men had developed severe erectile dysfunction, possibly because the infection reduced blood supply to the penis.

Notably, one of the men had only mild symptoms of COVID-19. The other had been hospitalized. This suggests that even those with a relatively mild case of the virus may experience severe erectile dysfunction after recovery.

These results are not entirely surprising. After all, scientists know that other viruses invade the testes and affect sperm production and fertility.

An example: investigators who studied the testicular tissues of six patients who died of the SARS-CoV virus in 2006 found that all of them exhibited widespread cell destruction, with little or no sperm.

It is also known that the mumps and Zika viruses can enter the testes and cause inflammation. Up to 20% of men infected with these viruses will have impaired sperm production.

New vaccine safety study

Further research done by my team has brought some welcome news. A study of 45 men showed that Pfizer and Moderna mRNA vaccines appear safe for the male reproductive system.

So that’s another reason to get vaccinated – to preserve male fertility and sexual function.

Granted, research is only a first step into how COVID-19 might affect men’s sexual health; the samples were small. Studies should continue.

Still, for men who have had COVID-19 and subsequently experienced testicular pain, it is reasonable to consider that the virus has invaded the tissues of the testes. Erectile dysfunction can be the result. These men should see a urologist.

I also think the research presents an urgent public health message to the United States regarding COVID-19 vaccines.

For the millions of American men who are still unvaccinated, you may want to think again about the consequences if and when this very aggressive virus finds you.

One of the reasons for the reluctance to vaccinate is the perception among many that COVID-19 injections could affect male fertility. Our research shows the opposite. There is no evidence that the vaccine damages a man’s reproductive system. But ignoring the vaccine and contracting COVID-19 could very well do it.

This article originally appeared on The Conversation.