Pfizer, Moderna COVID vaccines do not decrease sperm count, study says
Fertility concerns surrounding the COVID-19 vaccines aren’t exclusive to women. Men are worried, too.
Seeking to dispel these fears, researchers at the University of Miami conducted a study to assess men’s fertility after vaccination and found no negative effects on their sperm.
From Dec. 17, 2020, to Jan. 12, 2021, they recruited 45 healthy volunteers ages 18 to 50 who were scheduled to get the Pfizer or Moderna vaccine, according to the study published in JAMA Network.
The participants were prescreened to ensure they had no previous or underlying fertility issues. Semen samples were taken before the first vaccine dose and approximately 70 days after the second, which is about how long sperm takes to regenerate.
Scientists analyzed semen volume, sperm concentration, sperm motility and total sperm count and found no significant decrease in any of these parameters compared with the samples taken before the COVID-19 shots.
“It was an unknown area that was making guys nervous to get the vaccine,” said study co-author Jesse Ory, urology fellow in infertility/andrology at the University of Miami Miller School of Medicine.
Despite the low sample size, the results were in line with what health experts expected. According to the study, eight participants who had low sperm counts before getting vaccinated recorded normal levels of sperm in their second sample.
“That’s not saying the vaccine increased sperm,” Ory said. “But even in guys who have low sperm count who may be worried about their fertility, they don’t need to worry that this vaccine will impact their fertility any further.”
The Centers for Disease Control and Prevention says there’s no evidence that any vaccines, including the ones against COVID-19, cause male or femaleinfertility. However, the only fertility studies the agency published on its website looked at females and pregnancy outcomes. The University of Miami study is the first to look at COVID-19 vaccines and sperm count, Ory said.
“Men are half the couple,” said Dr. Sigal Klipstein, chair of the ethics committee at the American Society of Reproductive Medicine, who is not affiliated with the study. “Men have just as much impact on fertility as women, and it’s important to make sure that their concerns are addressed as well.”
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Though it’s clear the vaccines don’t cause infertility, Klipstein said it’s possible severe COVID-19 could influence sperm count if someone has a prolonged fever.
“Getting COVID can be potentially detrimental to their fertility, and getting the vaccine is safe and could even protect fertility by protecting you against the severe effects of COVID disease,” she said.
Although health experts assumed COVID-19 vaccine wouldn’t have any impact on fertility, Klipstein said potential concerns should be investigated.
“It’s still important to study questions even if we think we know the answers,” she said. “It gives us added reassurance that what we assumed to be true is actually true.”
Follow Adrianna Rodriguez on Twitter: @AdriannaUSAT.
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