Can the Covid-19 Vaccine Make You Infertile? This is what stubborn rumors claim, which have been circulating on social networks for several months. Despite the lack of evidence to support this theory, it has met with some success, especially in the United States.

Nearly two-thirds of people who say they are sure they will not get the vaccine worry about the impact on their fertility, according to one survey by the American Kaiser Family Foundation published in early May. However, there is no scientifically established link between vaccination and infertility.

A vaccine that would prevent the production of the placenta?

These fears around fertility arose from a letter, written by two doctors, Wolfgang Wodarg and Mike Yaedon. In this petition to the European Medicines Agency in December 2020, the two doctors worried because one of the proteins necessary for the manufacture of the placenta, syncytin 1, resembles the spike protein, the key that allows the coronavirus to enter our bodies.

However, vaccines lead to the production of antibodies, intended to fight against this protein. For the two doctors, there is therefore a risk that the body will “make a mistake” and start producing antibodies against syncytin, making it impossible to manufacture the placenta, and therefore pregnancy.

A hypothesis that is not based on any scientific study: the petition itself mentions that, for the moment, nothing indicates that this confusion of the antibodies could occur. The two doctors just claim that “if it was the case”, it could lead to infertility in millions of women.

A fake news taken over by a French doctor

On the networks, the assumption of the two doctors quickly becomes an assertion: the vaccine against the covid-19 makes sterile. The fake news is spreading: on Facebook, we can read that 97% of vaccinated people become sterile or that simple intercourse with a vaccinated man can be enough to permanently harm a woman’s fertility.

In France, this fake news is taken up by Dr Louis Fouché, an anesthesiologist in Marseille in an interview with Nexus, a magazine “Devoted to pseudosciences and quick to relay unfounded allegations” according to the AFP fact checking service. Close to conspiratorial circles, he says in the video, posted on Facebook, that the “syncitin problem” pose a “risk of infertility”.

No evidence or scientific basis

The exclusion of pregnant women from early clinical trials helped create these fears, which are nothing new. “They are content to recycle the elements which, for existing vaccines, were already a source of concern, even if this is not based on any scientific basis.”, says Devon Greyson, professor at the University of Massachusetts Amherst.

“There is no evidence to suggest that the vaccine can cause infertility”, reassure theAmerican College of Obstetricians and Gynecologists. But the American vaccination campaign is blaming the blow: among 18 to 49 year olds, 50% of women express fears that “the covid-19 vaccine may have a negative effect on their fertility in the future”.