Fact Check-No evidence that COVID-19 vaccines affect male fertility

A series of tweets posted by Scottish television personality Gillian McKeith on Nov. 15 suggests that men who have not been vaccinated against COVID-19 have more valuable sperm than those who have.

The first (here) says: “Non jabbed men! You have an extremely valuable commodity. So your duty to your country and the future of humanity is to #HoldTheLine We are counting on you…!”

The second (here), which simply reads “Hear hear!!”, quotes a tweet from a different account that includes a picture of a man at a protest holding a sign that reads: “Unvaxxed sperm is the next Bitcoin.”

The third (here), which includes a gif of a swimming sperm cell, says: “If you have a non jabbed version of what you see here… can name your price! #HoldTheLine Your country needs you!”

McKeith has previously come under fire for supporting anti-lockdown protests in London (as reported here and here) and for suggesting that healthy eating can provide natural immunity against COVID-19 (see tweet here and report of criticism here).

There is no evidence that the sperm of vaccinated men is affected – and therefore less valuable. Nor are vaccinated men discouraged from donating sperm.

Dr Ying Cheong, a professor of reproductive medicine and medical director at Complete Fertility clinic, told Reuters via email that the suggestion was “appalling”.

She said: “I am not aware of any literature suggesting this and would suspect these are largely unfounded and, if there were studies, they must be non-controlled small sample size studies in non-mainstream journals.

“It is important we stop these unfounded studies from spreading poor quality data. Ms McKeith might think this is ‘funny’, but it is not really a joke.

“We now have patients insisting to know a donor’s vaccination status. Also, if donors do not have vaccination just because of this fake news, their health could be in jeopardy.”

Dr Ramy Abou Ghayda, the chief medical officer for U.S.-based digital fertility clinic Legacy ( and, also told Reuters via email that it “will not discriminate against any client, in any financial or non-financial way, based on their vaccination status”.

He added: “We have enough data and a decent body of scientific evidence at this point that refute any potential negative correlation of COVID-19 vaccines on semen parameters. In all the studies that have been published so far in reputable medical journals, COVID-19 vaccines did not have any harmful impact on semen parameters, including sperm volume, concentration, motility and morphology.”

Legacy also published a Q&A on COVID-19 vaccines and male fertility on Jul. 19, 2021 (here), which states: “The COVID-19 vaccines will not alter male fertility; multiple studies demonstrate that being vaccinated has no effect on sperm count or motility (sperm capability to move/swim).”

Similarly, the Human Fertilisation and Embryology Authority (HFEA), a non-departmental public body of the UK’s Department of Health and Social Care (DHSC), says it is safe for men to donate their sperm if they have had the coronavirus vaccine (here). Similarly, the Cardiff and Vale University Health Board says: “COVID-19 vaccines do not contain any virus and so you cannot pass on COVID-19 (via sperm or egg donation) by receiving the vaccine.” (here)

The Journal of the American Medical Association (JAMA) published a peer-reviewed University of Miami Miller School of Medicine study on June 17 (here) that found that a group of healthy men who had received two doses of the mRNA vaccines (Pfizer or Moderna) showed “no significant decreases” in their sperm count and movement.

It concluded: “Because the vaccines contain mRNA and not the live virus, it is unlikely that the vaccine would affect sperm parameters.”

However, the authors of the paper acknowledged the sample group was small and their conclusions had “limited generalisability beyond young, healthy men”.

Citing the University of Miami study, the U.S. Centers for Disease Control and Prevention (CDC) guidance (here), most recently updated on Nov. 11, 2021, says: “Currently no evidence shows that any vaccines, including COVID-19 vaccines, cause male fertility problems… Researchers found no significant changes in these sperm characteristics (quantity and movement) after vaccination.”

Emma Duncan, Professor of Clinical Endocrinology at King’s College London, told the ZOE COVID Study (here from Sep. 28, 2021) that contracting coronavirus is worse for fertility than potential side effects from the jabs.

She said: “The question of male fertility and COVID-19 vaccines has been studied for mRNA vaccines; and there is no evidence that sperm counts or motility or male fertility are affected by vaccination. There have been no concerns raised about AstraZeneca to date either.

“However, what is important is that there is evidence that men who are recovering from moderately severe COVID-19 have reduced sperm quality and counts 1-2 months after their illness, compared with men who have mild or asymptomatic infection – though in the study that looked at this, the values were still in the normal range and may recover further with time.”

Finally, Dr Albert Hsu, a reproductive endocrinologist at MU (University of Missouri) Health Care (here) said that “while studies are ongoing, there is no data that the COVID-19 vaccines may cause infertility”. He told MU Health in an un-dated article (here) that men should get the jabs “as there are some concerns about the potential effect of COVID-19 disease on male fertility”.

Reuters has addressed previous claims about COVID vaccines and treatments affecting male fertility and sperm in fact checks here and here, plus in a news report here.


Missing context. There is no evidence that the sperm of unvaccinated men is more viable than that of vaccinated men. COVID-19 vaccines do not impact sperm counts or movement, whereas contracting the virus could.

This article was produced by the Reuters Fact Check team. Read more about our fact-checking work   here.