Video misrepresents study on COVID-19 vaccines and male fertility

CLAIM: A new study shows that a second dose of a COVID-19 vaccine reduces sperm count and after a third shot “it is almost irreparable.”

AP’S ASSESSMENT: Partly untrue. A new Israeli study did report a decrease in sperm count about three months after a second dose of Pfizer’s vaccine – but the effect was temporary and disappeared in subsequent samples. Experts say it is likely due to a fever, which may follow vaccination or infection and may temporarily affect sperm production. The Israeli study did not investigate the effects of a third dose.

THE FACTS: In a widely-watched video shared on Instagram this week, one man claims that “sperm count in men decreases rapidly and it’s all because of the vaccine.”

“New studies have shown that after the second shot there is a 22% decrease in sperm count and after the third shot, after the third booster, it is almost irreparable,” he continues. “Almost half a billion men have been vaccinated. What is going to happen to society now? ”

A recent Israeli study in the journal Andrology did find that three months after the second dose of Pfizer’s vaccine, there was a temporary decrease in sperm count of about 22% among donor samples.

But an author of the study told The Associated Press the findings were not a cause for concern, and are typical of what is seen with a fever.

“The observation we saw, which is characterized by ‘window’ of shortening 3 months after vaccination, is very similar to previously reported sperm decrease after common feverish diseases (such as flu),” Dr. Itai Gat, of the Shamir Medical Center in Israel, said in an email.

The researchers found at six months that the reduction “disappears,” Gat said. “We have come to the conclusion that impairment is temporary and long-term outcome remains good.”

In a 2021 statement on the COVID-19 vaccines, two organizations focused on male reproduction have also noted that fever in general – including due to COVID-19 infection or vaccination – can temporarily affect sperm production.

“Fever can cause temporary declines in sperm production,” reads the statement from the Society for Male Reproduction and Urology and the Society for the Study of Male Reproduction. Thus, if a man experiences fever due to the COVID-19 vaccine, he may experience a temporary decrease in sperm production, but this will be similar to or less than when the individual experiences fever due to the development of COVID -19 or for other reasons. ”

Dr. Ranjith Ramasamy, Director of Reproductive Medicine and Surgery at the University of Miami’s Health System, working separately researched the issue, told the AP the Israeli study was small but added interesting information to the field.

This “will be one of the first to demonstrate that COVID-19 vaccines (specifically Pfizer) could lead to a decrease in sperm parameters in the short term,” Ramasamy said in an email.

Importantly, the authors note that unlike the actual SARS-CoV-2 virus which can cross the blood testis barrier and affect the local testicular environment – these temporary decreases described in this study are most likely attributed to the fever. which some people experience with vaccination, ”Ramasamy said.


It is part of AP’s effort to address widely shared misinformation, including working with outside companies and organizations to add factual context to misleading content circulating online. Learn more about fact checking at AP.

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