CLAIM: Pfizer warns people not to have unprotected sex after the second COVID-19 vaccine dose for up to 28 days because of the risk of “birth defects due to genetic manipulation.”

THE FACTS: A TikTok video that claims the Pfizer vaccine can cause birth defects resurfaced this week after a large study was published last week and provided further evidence that the COVID-19 vaccines made by Pfizer and Moderna are safe for pregnant women. The false claim began circulating in December. “Page 132 of Pfizer vaccine..basically says no unprotected sex up to 28 days after 2nd dose due to reproductive safety risk..this is for males and females..births defects due to genetic manipulation,” text in the video falsely states. The AP has debunked posts claiming the COVID-19 vaccine can alter DNA. The U.S. Food and Drug Administration granted emergency authorization for Pfizer’s COVID-19 vaccine in December. Before that, the vaccine was tested in clinical trials that excluded pregnant women. Page 132 of a Pfizer protocol document instructs clinical trial participants to take measures to avoid becoming pregnant or getting someone pregnant “for a minimum of 28 days after the last dose of study intervention.” Pfizer began testing the COVID-19 vaccine on pregnant women in February. Medications and vaccines are typically tested first in young, healthy people who are not pregnant or at risk of getting pregnant, said Dr. Andrea L. Cox, a professor of medicine at the Johns Hopkins University School of Medicine. Once proven to be safe among healthy adults who are not pregnant, drugs and vaccines can be tested on pregnant people, children and more vulnerable populations. “Whenever clinical trials are run and usually, again, no matter what you’re testing, there is a higher safety bar set for pregnant people because it’s key that we know something before we put a developing, potentially a developing fetus at risk as well as the pregnant woman,” Cox said. Dr. Arnold Monto, a professor of epidemiology at the University of Michigan School of Public Health, said there was nothing unusual about Pfizer’s instructions to clinical trial participants. “I think the wording on contraception is pretty typical of an early study when you are being cautious,” Monto said.

— Arijeta Lajka