How the COVID-19 virus and vaccines may affect fertility, especially in men

Host Amber Smith: Be The Informed Patient with Upstate Medical University's podcast on health, science and medicine. This is your host, Amber Smith. One of the ongoing concerns about COVID-19 is how and whether the disease or the vaccine has an impact on fertility. Today, I'm speaking with an expert who has researched fertility for a good portion of his career.

Dr. Kazim Chohan is a professor of pathology and obstetrics and gynecology at Upstate and also the director of andrology. Welcome back to The Informed Patient podcast, Dr. Chohan.

Kazim Chohan, PhD: Thank you very much, Amber. And I appreciate it.

Host Amber Smith: Well, before we get into fertility, let me ask you why it seems that men suffer more than women do if they get infected with COVID-19.

Kazim Chohan, PhD: Amber, when COVID came, we saw that men studies showed that men are having more severe symptoms with COVID, and their death rate was high. And that initiated an issue that if men are suffering more with COVID, then certainly they will also have an effect on their fertility.

But when it goes to why men suffer more, there are two bases for that. One is biology behind that. The other one is lifestyle issues on that. In terms of biology, there are two different hormones. Women have mainly estrogens, and estrogens have a quality that they promote both innate and adaptive immune responses, and they lead to a faster clearance of pathogens.

They help, the estrogens help, to have less severe symptoms in women, and they have more robust immune response to vaccines. When it comes to men, testosterone is the main culprit. Increased levels of testosterone have a suppressive effect on immune system. Estrogen and testosterone behave differently when it comes to immune responses.

And on top of that, when we see that men who suffer more, they are having underlying causes like diabetes, blood pressure or lung diseases. So a decrease in testosterone level is another factor, and decreasing levels of testosterone upregulate the receptors for angiotensin ACE2.

And this is the main receptor for coronavirus. And these are the two things: When it comes to the other issues or when the testosterone level goes down, the receptors for the ACE2 angiotensin are increased in men. And it goes to lifestyle issues. Men are more prone to like jobs like driving.

They get more exposure outside. They smoke more, and their lung capacity is poorer than women's. Studies have shown that women are more responsible when it comes to social distancing or using masks and all that. So all these things that play a major role in the severity of this disease, and based on these things, we can now see, and many studies show, that men suffer more than women.

Host Amber Smith: So did I hear you correctly? The male hormone testosterone has the effect of reducing the immune system's ability to work?

Kazim Chohan, PhD: That's true. Yeah.

Host Amber Smith: So tell me how might getting infected with COVID-19 affect fertility for men and for women, because I know it may be different.

Kazim Chohan, PhD: Yes. Biologically, when it comes to fertility, this is different. The system is different for both. In men, spermatogenesis takes place in the testes all the time. Testes have three major cells. One is Leydig cells. These cells produce testosterone, and they have receptors for ACE2. And they can suffer from coronavirus. Once they are affected, the gentleman can go low on testosterone levels, and these load-decreasing testosterone levels will upregulate ACE2 receptors in general, in that person.

But on top of that, once they are affected, spermatogenesis will be directly affected, and to save these sperm cells, sperm cells are haploid in nature. There is a blood-testis barrier, which is made of gap junctions and myeloid cells. And in there, there are Sertoli cells, which are mother cells or nurturing cells for spermatagonia.

Once that blood-testis barrier is broken, then the gentleman may have orchitis, inflammation in the testes, there, but this happens in rare cases, mostly. So far, We have seen in 3% cases when the patient is having severe impact on that. But the major effect, the normal thing we can see, is that the major symptom in coronavirus infection is fever. In patients who suffer with febrile conditions, normally they have semen parameters go down over period of time during that infection or inflammatory period. Same will happen in coronavirus infection, that due to high fever, spermatogenesis will be affected. The semen parameters will go down. They may affect motility, sperm morphology, and there is a chance that that will increase from DNA fragmentation.

On the female side, heart cycles, menstrual cycle may be affected, but there's the menses of the reproductive cycle in a female is different than a man's. She only produces one oocyte per month, or max, maybe two, a limit of one or two. So they both behave differently, and biology for both of them are different. In this case, men will suffer more when it comes to fertility compared to women.

Host Amber Smith: So it's a higher risk for men to have their fertility impacted if they get sick with COVID-19?

Kazim Chohan, PhD: Absolutely.

Host Amber Smith: So what about getting the vaccine? Does the vaccine have any impact on fertility?

Kazim Chohan, PhD: So far, a research study showed the results that actually vaccines have no effect on fertility.

They have a positive effect in terms that these semen parameters were evaluated in a clinical study that they evaluated semen parameters before vaccines and after vaccines. Actually, they found improved semen parameters after vaccines. So there is just a biological difference. We cannot say that vaccine improves semen parameters and makes men more fertile, but that indicates that vaccinations are beneficial in men and there is no impact on fertility.

And when it comes to females, they figured out that it's very positive. A woman, once she is vaccinated, she gets antibodies on day five of vaccination, and the fetus gets antibodies on the 16th day of vaccination. So vaccinations are actually beneficial for both men and women equally.

This is Upstate's "The Informed Patient" podcast. I'm your host, Amber Smith, talking with a fertility expert, Dr. Kazim Chohan. If someone had COVID-19, is it safe for them to try to conceive, or do they need to wait a certain period of time?

When we talk about fertility in terms of males, as we said, males (are) affected more with this COVID-19. There is a spot, a time period for men, this is called spermatogenic cycle, which is around 70 days. So if someone gets COVID-19, I will suggest that that person should stay away from any sexual activity if they are, trying to conceive ,or at least use some protection for at least three months.

The reasons are the major symptom of COVID-19 is fever. Any febrile condition can affect spermatogenesis. That we normally see like if someone is having fever or patients having some varicoceles and all these kinds of conditions. So in these issues, semen parameters will go down and sometimes we get like sperm function goes down and patients may have some like sperm DNA fragmentation. To avoid all these things, based on my experience, I suggest at least they should avoid to conceive at least for three months. Once they pass one spermatogenic cycle, I hope they will be fine.

Host Amber Smith: So if I hear you correctly, the virus could affect the quality of a man's semen?

Kazim Chohan, PhD: Absolutely.

Host Amber Smith: What about the vaccine? Does that have any impact on the quality of a man's semen?

Kazim Chohan, PhD: One of the controlled studies, the data came out, and it showed that the vaccines have no negative effect on semen parameters in men, actually the results from most coronavirus vaccines showed better results when it came to sperm concentrations, motility and morphology, but the difference was not huge. And this may be a biological difference. The bottom line is that vaccines actually help to maintain, help to kind of keep the fertile potential of a male. And they have no negative effect on fertility.

Host Amber Smith: So just to sum up from what you've been saying, if you're a male who wants to have children and you've been infected with COVID-19, what is your advice for that person?

Kazim Chohan, PhD: When it comes to fertility, our patients are in two groups. One group is patients who are in fertile age.

And there is a group of patients who have crossed the fertility age, and these people are maybe over mid-40s, 50s, 60s -- mostly these people have underlying causes and they will suffer most due to COVID-19. When it comes to a group who are in fertile age and who are concerned about fertility, these are the people in their 20s, 30s, 40s, who are planning to have a family. If one of them suffers from COVID-19, my suggestion is that that person should avoid or should have protected sex for at least 70 days -- one spermatogenic cycle. And once that spermatogenic cycle passes away, he will have normal semen parameters.

That's how this will go until or unless he gets like very badly affected by COVID-19 and gets orchitis and that kind of stuff. For an average normal population, they will have normal semen parameters once they pass that one spermatogenic cycle.

Host Amber Smith: Should a person who's planning to become pregnant or who is pregnant, should they get vaccinated?

Kazim Chohan, PhD: Absolutely. They should go for vaccination. That's the best way to go.

Host Amber Smith: And were you saying that the vaccine that the mother would get would protect the baby as well?

Kazim Chohan, PhD: There are many studies out there that the vaccines have protective effect, both for the mother and for the fetus, and the mothers transfer antibodies to the fetus. These antibodies, they pass the placenta, and babies are saved with that, too.

Host Amber Smith: So when the baby is born, the baby would already have some immunity to the SARS-CoV-2 virus?

Kazim Chohan, PhD: That's what biology tells us.

Host Amber Smith: Now looking further out, is there any evidence or any suspicion that the vaccine could have an impact on the fertility of the child later on, once they're an adult?

Kazim Chohan, PhD: Well, a recent survey came out in October, on Oct. 28, from the Kaiser Foundation, and they figured out that still three out of 10 parents will not have their child vaccinated.

And the 66% of parents of these three out of 10, their concern was that their baby will have an effect on the fertility due to vaccine. But we have to consider one thing, that these vaccines are against immune response. They are not against the reproductive system. So having vaccination for the children will not have any negative impact on their fertility.

Host Amber Smith: I appreciate you making time for this interview. Dr. Kazim Chohan leads the andrology lab at Upstate, where he's a professor of pathology and of obstetrics and gynecology. I'm Amber Smith for Upstate's The Informed Patient podcast.