Researchers at the University of Miami studied the sperm quality of 45 healthy volunteers before their first shot and 70 days after their second, and found there were no “significant decreases in any sperm parameter” after taking two doses of the mRNA vaccine.
“Because the vaccines contain mRNA and not the live virus, it is unlikely that the vaccine would affect sperm parameters,” said study author Dr. Ranjith Ramasamy, director of male reproductive medicine and surgery at the University of Miami Health System.
The findings, which were published Thursday in the Journal of the American Medical Association, should soothe fears of men who are reluctant to get inoculated over premature reports of fertility issues, doctors said.
“We now have evidence that should reassure you that the risk of immunization compromising your sperm count is extremely low,” Dr. David Cohen, co-medical director of the Institute for Human Reproduction in Chicago, told Fintech Zoom.
Cohen was not involved in the latest JAMA study, but co-authored an April medical report that found COVID-19 is not transmitted sexually.
The author of the study conceded that its findings might be limited by its small sample size of pre-screened young, healthy men, adding that semen analysis “is an imperfect predictor of fertility potential.”
The volunteers were between 18 to 50 years old with a median age of 28. They had no pre-existing fertility issues.