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You’re pregnant, healthy and hearing mixed messages: Health and Human Services Secretary Robert F. Kennedy Jr., removed the COVID vaccine from the list of vaccinations you should get.
“I couldn’t be more pleased to announce that as of today the COVID vaccine for healthy children and healthy pregnant women has been removed from the CDC recommended immunization schedule” Kennedy said on Tuesday.
But guidance from the Centers for Disease Control and Prevention and other researchers say being pregnant still puts you in a high-risk group that should receive boosters. The science is on the side of the shots.
COVID in pregnancy
Pregnant women who contracted COVID were more likely to become severely ill and to be hospitalized than women of the same age and demographics who weren’t pregnant, especially early in the COVID pandemic.
An analysis of 435 studies from around the world in 2019-2020 found that pregnant and recently pregnant women who were infected with COVID were more likely to end up in intensive care units, be on invasive ventilation, and die than women who weren’t pregnant but had a similar health profile. This was before vaccines were available.
Dr. Neil Silverman, a professor of clinical obstetrics and gynecology, directs the Infectious Diseases in Pregnancy Program at the David Geffen School of Medicine at UCLA. He said he still sees more bad outcomes in pregnant patients who have COVID. The risk of severe COVID fluctuated as new variants arose and vaccinations became available, Silverman said, but the threat is still meaningful.
“No matter what the politics say, the science is the science, and we know that objectively, pregnant patients are at substantially increased risk of having complications,” Silverman said.
A request for comment regarding the scientific literature that supports COVID vaccination for pregnant women sent to HHS’s Public Affairs office elicited an unsigned email unrelated to the question. The office did not respond when asked for an on-the-record comment.
There’s still a lot unknown about how COVID affects a pregnant person. The physiological relationship between COVID infections, mothers and fetuses at different stages of a pregnancy is complex, said Angela Rasmussen, a virologist at the University of Saskatchewan.
The increased risk to pregnant patients comes in part because pregnancy changes the immune system, Rasmussen said.
“There is natural immune suppression so that the mother’s body doesn’t attack the developing fetus,” Rasmussen said. “While the mother does still have a functioning immune system, it’s not functioning at full capacity,” she added.
Pregnant patients are more likely to get sick and have a harder time fighting off any infection as a consequence.
COVID can harm the placenta
In addition to changing how the immune system works, being pregnant also makes women five times more likely to have blood clots. That risk is increased if they contract COVID said Sallie Permar, Chair of Pediatrics at Weill Cornell Medicine.
The virus that causes COVID can affect the vascular endothelium – specialized cells that line blood vessels and help with blood flow, Rasmussen said. In a healthy person, the endothelium helps prevent blood clots by producing chemicals that keep the vascular system running. In a person infected with COVID, the balance is thrown off and the production of those molecules is disrupted, which research shows can lead to blood clots or other blood disorders.
Permar said that those clots can be especially dangerous to both the pregnant women and baby. Inflammation and blood clots in the placenta could be connected to an increased risk of stillbirth especially from certain COVID variants, according to studies published in major medical journals as well as by the CDC.
When the placenta is inflamed, it’s harder for blood carrying oxygen and nutrients to get to the baby, said Mary Prahl, associate professor of pediatrics at the University of California San Francisco School of Medicine.
“If anything is interrupting those functions – inflammation or clotting or differences in how the blood is flowing – that’s really going to affect how the placenta is working and being able to allow the fetus to grow and develop appropriately,” she said.
It makes sense that we see the effects of COVID in the placenta, Silverman said. “The placenta is nothing more than a hyper-specialized collection of blood vessels, so it is like a magnetic target for the virus.”
Blood vessels in the placenta are smaller, thinner and clot more easily than in the mother’s circulatory system, he said.
Permar said more recent data suggests that pregnant women sick with COVID still have a higher risk of pregnancy complications such as preeclampsia, preterm birth, and miscarriage, even with existing immunity from previous infection or vaccination. Covid, she said, can still land women in the hospital with pregnancy complications.
Prahl said the connection between stillbirth and COVID may be changing given the immunity many people have developed from vaccination or prior infection. It’s an area in which she’d like to see more research.
Vaccine safety and efficacy
There’s already strong evidence that both mRNA-based and non-mRNA COVID vaccines are safe for pregnant women.
Prahl co-authored a small, early study that found no adverse outcomes and showed antibody protection persisted for both the mother and the baby after birth. “What we learned very quickly is that pregnant individuals want answers and many of them want to be involved in research,” she said. Later studies, including one published in the journal Nature Medicine showing that getting a booster in pregnancy cut newborn hospitalizations in the first four months of life, backed up her team’s early findings.
Prahl expects more evidence will be available soon to support the benefits of mothers receiving a COVID booster during pregnancy.
“I can say kind of behind the scenes, I’m seeing a lot of this preliminary data,” she said.
She blames the delay in part on the Biden administration’s scaling back of federal efforts to track COVID. “A lot of the surveillance of these data were pulled back,” she said. The Trump administration is further cutting money used to track COVID.
But because the vaccine gives a pregnant woman’s immune system a boost by increasing neutralizing antibodies, virologist Rasmussen is confident that getting one while pregnant makes it less likely a pregnant woman will end up in the hospital if she gets COVID.
“It will protect the pregnant person from more severe disease,” she said.
Getting a COVID vaccine while pregnant also helps protect newborns after birth. Pregnant women who get vaccinated pass that protection to their infants.
According to recent data from the Centers for Disease Control and Prevention, nearly 90% of babies who had to be hospitalized with COVID-19 had mothers who didn’t get the vaccine while they were pregnant. The study drew upon medical data in 12 states, collected between October 2022 and April 2024. Of the 1,470 infants sick enough to be hospitalized due to COVID, severe outcomes occurred “frequently” according to the report.
Excluding newborns hospitalized at birth, about 1 in 5 infants hospitalized with COVID required intensive care, and nearly one in 20 required a ventilator.
And babies too young to be vaccinated had the highest COVID hospitalization rate of any age group except people 75 and over.
The Trump administration’s decision to remove the COVID vaccine from the list of shots it recommends for pregnant women means insurance companies may no longer cover it–so it may cost hundreds of dollars out of pocket.
“I don’t want to be that doctor who just says, ‘Well, it’s really important. You have to vaccinate yourself and your kids no matter what, even if you have to pay for it out of pocket,’ because everyone has their own priorities and budgetary concerns, especially in the current economic climate,” Silverman said. “I can’t tell a family that the vaccine is more important than feeding their kids.”
But he and his colleagues will keep advising pregnant women to try to get the shots if they can.
“Newborns will be completely naïve to COVID exposure,” he said. “Vaccinating pregnant women to protect their newborns is still a valid reason to continue this effort.”
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