Is COVID vaccination safe in pregnancy? What Dr. Fauci's texts show.
Three federal health officials had to extrapolate from other vaccines in January 2021 because COVID vaccine clinical trials excluded pregnant women.
The text the senators released.
On January 25, 2021 at 6:45 p.m., Dr. Anthony Fauci texted the new CDC director and the surgeon general nominee. Drug companies had excluded pregnant women from the COVID vaccine trials. The three of them were trying to work out what advice to give women.
“Since many people have significant cytokines storm and fever after the 2nd dose,” he wrote, “this theoretically could be associated with miscarriage in the 1st trimester.”
Senators Ron Johnson and Rand Paul released that text message on Monday. It came off a government phone that HHS turned over to Sen. Johnson’s investigators on August 5th. On August 6th, the Senate Homeland Security and Governmental Affairs Committee voted along party lines to hold Dr. Fauci in contempt for taking the Fifth.
Dr. Fauci said theoretically. The next day, in the same text thread, he wrote that the benefits outweighed the risks. More than 10,000 pregnant women had already been vaccinated, he said, and no issues had come up.
The evidence that already existed.
More than the text thread suggests.
In 2009, drugmakers made a new H1N1 swine flu vaccine in months. Health systems gave it to pregnant women across Europe and the US. Denmark followed 54,585 pregnancies and found no increase in fetal death or miscarriage. Norway followed 117,347 pregnancies. There, getting the flu raised the risk of fetal death. The vaccine did not.
A Danish study of 24,040 pregnancies found no link between fever in the first 16 weeks of pregnancy and fetal death. That held no matter how high the fever ran, how long it lasted, or when in those 16 weeks it hit.
Pregnant women also get fewer reactions to vaccines than they do outside pregnancy. A randomized trial of Tdap found those reactions in 36% of women vaccinated during pregnancy; in women given the same shot after delivery, 73%.
None of this provided evidence on whether the lipid nanoparticle was safe. That part was new.
Who kept pregnant women out of the trials?
In 2013, a review of industry clinical trials found that 348 of 367 excluded pregnant women. In 2018, a federal task force created by Congress told the Secretary of Health and Human Services to fix it. By June 2020, before any vaccine existed, 829 of 1,282 COVID treatment trials had already excluded pregnant women.
What the data eventually showed.
An analysis of 21 studies and 149,685 women found no rise in miscarriage. France followed 130,338 infants exposed in the first trimester. No rise in birth defects, across all 75 categories they checked. A US case-control study looked specifically at women who’d had both doses and found nothing.
In Scotland, 98% of pregnant women who ended up in critical care with COVID were unvaccinated when they were diagnosed. So were all the women whose babies died.
Dr. Andrea Edlow is a maternal-fetal medicine physician at Massachusetts General Hospital. She runs a lab there on pregnancy and the immune system. She has studied this question since the first COVID shots went into arms. “We have very strong evidence, now longstanding, that the COVID-19 vaccine in pregnancy is not associated with miscarriage,” she told me. “The recirculation of these old anti-vaccination tropes is especially wrong at this point in time when we have the benefit of many years of experience.”
Before 20 weeks, after 20 weeks.
Dr. Vivek Murthy, then Biden's nominee for surgeon general, asked whether it was better to vaccinate early or late in pregnancy. Dr. Fauci answered that there was no data and no theoretical reason to prefer either.
The first half was true. The second half wasn’t, even in 2021. Researchers already knew timing mattered for maternal vaccines. It’s why doctors give Tdap between 27 and 36 weeks, so the antibodies reach the baby.
Babies whose mothers were vaccinated after 20 weeks were 69% less likely to be hospitalized with COVID; before 20 weeks, 38%. Antibodies cross the placenta at different rates depending on when the mother was vaccinated. Dr. Edlow’s lab has since found trimester-specific protein responses in maternal blood.
What about next time?
I asked Dr. Edlow whether pregnant women would be excluded again from the next new vaccine.
“I am concerned we would be in the same position,” she wrote back. “Particularly given the current environment in the country vis a vis vaccination safety in general. I wish that wasn’t the case and that we had learned this lesson from the COVID-19 pandemic. But I worry we have not.”
A group chat is now evidence in a Senate investigation because three federal health officials had to extrapolate from other vaccines instead having clinical trial results to inform their recommendations. In 2018, a federal task force told HHS to fix that. It is 2026.