A recent survey from Kaiser Health Foundation found that 66% of parents with children between the ages of 5 and 11 were worried that the COVID-19 vaccine may negatively impact their child’s fertility in the future.

This concern poses a serious challenge to getting most U.S. children vaccinated, which is a crucial part of increasing national vaccination rates and ending the pandemic. And it’s based on a claim experts say is simply untrue.

“There is no evidence that the Pfizer COVID vaccine—the one currently approved for children 5-11 years old—causes infertility,” Maria I. Rosas, MD, a pediatric infectious disease specialist with KIDZ Medical, told Verywell. “Neither the vaccine ingredients nor the antibodies made by your body after the vaccine affect fertility.”

Where Does the Misinformation Stem From?

The myth, which has been circulating on social media, originally came from a letter sent to the European Medicines Agency, according to Paul Offit, MD, a Food and Drug Administration (FDA) vaccine adviser.

The pediatrician and head of the Vaccine Education Center at the Children’s Hospital of Philadelphia said in a video that the letter contained an unfounded claim that there was a similarity between the SARS-CoV-2 spike protein and syncytin-1— a protein that sits on the surface of placental cells.

“So the thinking was, if you’re making an antibody response to that spike protein of coronavirus, you’re also inadvertently making an antibody response to this syncytin-1 protein on the surface of placental cells, which would then affect fertility,” Offit said in the video. “First of all, that wasn’t true. Those two proteins are very different. It’s like saying you and I both have the same social security number because they both contain the number five. So that was wrong, to begin with.”

COVID-19 Vaccines Don’t Impact Fertility

Alan Copperman, MD, a reproductive endocrinologist specializing in infertility, agrees that the claim is inaccurate.

“Given that there is no significant ‘similarity in structure’ between the spike protein and placental proteins, there is no risk of cross-reaction between antibodies against the spike protein and the placenta,” Copperman, who is the Medical Director at Progyny and co-founder of the Reproductive Medicine Associates of New York, told Verywell.

Recent studies looking at people who have tried to get pregnant after being vaccinated further prove that the vaccine does not affect fertility.

“There have been studies in women trying to get pregnant that show no difference in pregnancy success between people with natural immunity, vaccinated or unvaccinated,” Rosas said.

Due to the novelty of both COVID-19 and the vaccines, it’s too early to know with complete certainty what long-term effects may arise in the years to come. But reproductive endocrinologist Kaylen Silverberg, MD, told Verywell there is no data that indicates the COVID-19 vaccine can or does impact fertility.

“From our knowledge of how the vaccine works, there is no obvious mechanism by which the vaccine should be able to affect fertility,” he told Verywell. “After reviewing all of the data collected so far, the American Fertility Society, The American College of Obstetricians and Gynecologists, and the Centers for Disease Control and Prevention (CDC) all agree that there’s no evidence that the COVID vaccines impact infertility.”

Despite this fact, misinformation about vaccine side effects continues to circulate on social media. Experts advise you not to trust everything you see circulating on the web.

“As we have all have learned over the past few years, there is much information on social media that is unverified,” Silverberg said. “The best thing to do if you have concerns about the vaccine is to talk to your doctor. Physicians are well informed, and you should consider placing your trust in them rather than in unsubstantiated posts on the internet.”

The information in this article is current as of the date listed, which means newer information may be available when you read this. For the most recent updates on COVID-19, visit our coronavirus news page.