Do COVID vaccines affect male fertility? What to know after Aaron Rodgers’ comments
Rumors that COVID-19 vaccines affect both male and female fertility continue to fuel concerns among millions of people who remain hesitant to get vaccinated.
The Centers for Disease Control and Prevention and several other medical organizations have said there is “no evidence that any vaccines, including COVID-19 vaccines, cause fertility problems in women or men.”
However, popular voices, including artist Nicki Minaj and more recently Green Bay Packers quarterback Aaron Rodgers, often give renewed attention to common conspiracies that science has proven incorrect.
During a Nov. 5 appearance on the Pat McAfee Show Live, Rodgers said he did his own research and learned he’s allergic to an ingredient in the mRNA COVID-19 vaccines, including the Pfizer and Moderna shots, and was concerned about “adverse events” reported by some after vaccination with the Johnson & Johnson shot.
Among other issues the NFL superstar highlighted, potential fertility problems was among the top of his concerns.
“The next great chapter in my life, I believe, is being a father and it’s something that I care about a lot,” Rodgers said. “To my knowledge, there’s been zero long-term studies around sterility or fertility issues around the vaccines so that was definitely something that I was worried about.”
It’s true there aren’t any long-term studies analyzing how coronavirus vaccines affect male or female fertility. COVID-19 is a new disease that infiltrated the human population only about two years ago, so studies can only cover so much ground. There’s even more to learn about the long-term effects of the vaccines, which have only been around for about a year.
But the likelihood people will have difficulty reproducing five, 10 or even 20 years from now is low, thanks to how the vaccines work.
“In the entire history of vaccines, there’s never been a side effect that occurred more than two months after a vaccine was administered,” Dr. Wesley Long, medical director at Houston Methodist Hospital in Texas, said in an August blog post. “People are worried that some unknown side effect will occur 10 to 15 years down the line, but the truth is, that’s never happened.”
The Pfizer and Moderna vaccines do not contain live virus. Instead, they comprise mRNA, a molecule naturally found in our bodies that teaches our immune system to produce antibodies.
At no point does the vaccine interact with your DNA or cause genetic changes because the mRNA does not enter the nucleus of the cell, which is where your DNA is kept, according to the CDC.
The J&J vaccine injects a harmless virus called an adenovirus that has been genetically modified so it cannot make copies of itself in humans or cause disease.
All of this material, no matter the vaccine it comes from, is removed by your body within days, leaving only the instructions on how to attack the coronavirus if later exposed.
Studies show it’s COVID-19 — not vaccines — men need to worry about
Initial clinical trials for the Pfizer and Moderna vaccines did not evaluate the shots’ impact on fertility, yet early studies show vaccines are no cause for worry among men hoping to start or grow their family.
A University of Miami team analyzed the sperm of 45 healthy men between ages 18 and 35 before and after they received the Pfizer or Moderna COVID-19 vaccines. Sperm count — the most effective way to measure male fertility — did not decrease after vaccination, even among eight men who had low sperm count before their first dose, the Miami Herald reported.
Researchers with the American Society for Reproductive Medicine investigated 185 scientific articles on the topic and also found no evidence the shots have caused male infertility.
The group issued a joint statement with the American College of Obstetricians and Gynecologists and the Society for Maternal-Fetal Medicine in February that encouraged people planning on having a baby to get vaccinated against COVID-19.
“We assure patients that there is no evidence that the vaccine can lead to loss of fertility... no loss of fertility has been reported among trial participants or among the millions who have received the vaccines since their authorization, and no signs of infertility appeared in animal studies,” the groups said. “Loss of fertility is scientifically unlikely.”
Another source of misinformation stems from the well-known fact that fevers, a common side effect of COVID-19 vaccines, can cause temporary declines in sperm production. But experts say fever alone cannot damage a male’s reproductive success.
“If a man experiences fever as the result of the COVID-19 vaccine, he may experience a temporary decline in sperm production, but that would be similar to or less than if the individual experienced fever from developing COVID-19 or for other reasons,” the American Society for Reproductive Medicine said. “The COVID-19 vaccine should not be withheld from men desiring fertility.”
In the analysis of 185 articles on the topic, researchers found 76 that revealed COVID-19 itself may be impacting male fertility.
Some studies show the coronavirus can make its way into sperm, impact male hormones necessary for normal sperm production, trigger testicular or scrotal pain, and cause erectile dysfunction.
Doctors believe the male testes are targeted because they show “nearly the highest level” of ACE2 expression — a protein the coronavirus latches onto to infect people — among all tissues in the body, according to Houston Methodist urologist Dr. Nathan Starke.
In fact, several other viruses such as Ebola, Zika, herpes simplex, HIV, mumps and Epstein-Barr, are known to cause temporary or permanent fertility problems, Starke added.
“COVID-19 can be a life-threatening, long-lasting, enormous stressor on the body — including, yes, the gonads. In this pandemic, simply being male is a factor that puts you at higher risk of poor outcomes,” the Houston Methodist blog post said. “Male fertility and virility are personal issues, and doctors hope that raising awareness about their relationship to COVID-19 disease may help draw more attention to both the great risks of infection and the protective benefits of the vaccine.”
This story was originally published November 8, 2021 at 5:37 PM with the headline "Do COVID vaccines affect male fertility? What to know after Aaron Rodgers’ comments."
