Researchers Say HHS Memo to Congress Twisted Their Work to Back RFK Jr.'s Anti- Vaccine Agenda
By John Gregory
A memo sent to Congress by the U.S. Department of Health and Human Services misrepresented medical studies to justify the agency’s decision to stop recommending COVID-19 vaccines to pregnant women, the studies’ authors have told NewsGuard.
The HHS memo sent to lawmakers, which was first published by KFF Health News (NewsGuard Trust Score: 100/100) on June 13, 2025, includes a section about the scientific evidence that HHS Secretary Robert F. Kennedy Jr. relied on in his decision to remove the COVID vaccine from the recommended vaccine schedule during pregnancy.
The memo stated: “A number of studies in pregnant women showed higher rates of fetal loss if vaccination was received before 20 weeks of pregnancy.” A footnote said that this statement was based on a March 2024 study of 246,000 Canadian women published in the peer-reviewed British Journal of Obstetrics and Gynecology.
However, NewsGuard found that the study in question did not identify a link between COVID vaccination and an increased risk of miscarriage. The study’s lead author, Dr. Maria Velez, an associate professor of obstetrics and gynecology at McGill University in Montreal, confirmed this finding to NewsGuard.
“[T]he HHS document misinterpreted our study results,” Velez said in a June 16, 2025, email to NewsGuard. Asked if she believes that her work supported the new HHS recommendation that pregnant women should not get a COVID vaccine, Velez answered, “No, on the contrary, our study provides evidence to inform policy makers, healthcare providers, pregnant women and those considering a pregnancy about the safety of [COVID] vaccination in relation to miscarriage risk.”
Asked about the researchers’ charges that their work was misrepresented, HHS spokesperson Andrew Nixon defended the memo’s interpretation of Velez’s study. “The underlying data speaks for itself — and it raises legitimate safety concerns,” Nixon said in a June 18, 2025, email to NewsGuard. “HHS will not ignore that evidence or downplay early pregnancy loss. It is disturbing that NewsGuard appears to dismiss the significance of the underlying data. Every miscarriage is a tragedy. Suggesting otherwise is offensive to the families who have experienced that loss.”
However, as noted above, the study actually did not find that COVID vaccines were linked to miscarriages.
The HHS memo also stated, “Yet another study showed an increase in placental blood clotting in pregnant mothers who took the vaccine.” However, the research cited to back this claim — a study of the risk of COVID vaccine side effects that included 99 million people published in the journal Vaccine in February 2024 — contains no such data, NewsGuard found.
Again, a researcher who co-authored the study confirmed that the work was misrepresented.
“Our study does not even look at a cohort of pregnant women, and we don’t include ‘placental blood clotting’ as an outcome,” study co-author Anders Hviid, the head of epidemiological research at Denmark’s Statens Serum Institut, told NewsGuard in a June 16, 2025, email. Hviid added that the HHS memo’s interpretation of the study “is not particularly confidence inspiring.”
NewsGuard also asked the HHS press office about the study published in the journal Vaccine described above. Nixon, the HHS spokesperson, did not address this study in his June 18, 2025, email to NewsGuard. He defended the HHS memo more broadly in an earlier statement to KFF Health News, saying, “There is no distortion of the studies in this document.”
The HHS memo also did not mention the abundant evidence supporting the safety of COVID vaccines during pregnancy. Indeed, the website of the U.S. Centers for Disease Control and Prevention, an agency that Kennedy now oversees, states, “Studies including hundreds of thousands of people around the world show that COVID-19 vaccination before and during pregnancy is safe, effective, and beneficial to both the pregnant woman and the baby.”
False narratives about the purported dangers of COVID vaccines to pregnant women and their babies have been frequently promoted by anti-vaccine activists, including Kennedy, since the vaccines became available in late 2020.
NewsGuard’s RFK Jr. Healthcare Claims Depository, which has documented 106 provably false health claims advanced by Kennedy and the anti-vaccine nonprofit he founded, Children’s Health Defense, lists four false narratives related to COVID vaccines and pregnancy. These include claims that the vaccines have increased infant mortality rates and that they cause miscarriages.
This article was originally published in Reality Check’s newsletter. Subscribe to receive weekly updates straight to your inbox.