You鈥檙e pregnant, healthy, and hearing mixed messages: Health and Human Services Secretary Robert F. Kennedy Jr., who is not a scientist or doctor, the covid vaccine, but experts at the Centers for Disease Control and Prevention still put you in a of people who ought to receive boosters. The science is on the side of the shots.
Pregnant women who contracted covid-19 were more likely to become severely ill and to be hospitalized than non-pregnant women of the same age and demographics, especially early in the covid pandemic.
A of 435 studies found that pregnant and recently pregnant women who were infected with the virus that causes covid were more likely to end up in intensive care units, be on invasive ventilation, and die than women who weren鈥檛 pregnant but had a similar health profile. This was before covid vaccines were available.
, a professor of clinical obstetrics and gynecology and the director of the Infectious Diseases in Pregnancy Program at the David Geffen School of Medicine at UCLA, 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. 鈥淣o 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,鈥 Silverman said.
A request for comment regarding the scientific literature that supports covid vaccination for pregnant women sent to HHS鈥 public affairs office elicited an unsigned email unrelated to the question. The office did not respond when asked for an on-the-record comment.
Kennedy, a longtime anti-vaccine activist before joining the Trump administration, announced May 27 that covid vaccines would be removed from the CDC鈥檚 immunization schedule for healthy pregnant women and healthy children. His announcement, made in a video posted on the social media platform X, and circumvented the agency鈥檚 established, scientific processes for adding and removing shots from its recommended schedules, The Washington Post reported.
There鈥檚 still much unknown about how covid affects a pregnant person. The physiological relationship between covid infections and mothers and fetuses at different stages of a pregnancy is complex, said , a virologist at the University of Saskatchewan.
The increased risk to pregnant patients comes in part because pregnancy changes the immune system, Rasmussen said.
鈥淭here is natural immune suppression so that the mother鈥檚 body doesn鈥檛 attack the developing fetus,鈥 Rasmussen said. 鈥淲hile the mother does still have a functioning immune system, it鈥檚 not functioning at full capacity.鈥
Pregnant patients are more likely to get sick and have a harder time fighting off any infection as a result.
In addition to changing how the immune system works, being pregnant also makes women . That risk is increased if they contract covid, said , chair of pediatrics at Weill Cornell Medicine.
The virus that causes covid can affect the vascular endothelium 鈥 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 tweak the vascular system to keep it running. In a person infected with the covid virus, the balance is thrown off and the production of those molecules is disrupted, which can lead to blood clots or other blood disorders.
Permar said that those clots can be especially dangerous to both pregnant women and fetuses. Inflammation and blood clots could be connected to an increased risk of stillbirth, especially from , according to studies published in major medical journals as well as by the CDC.
When the placenta is inflamed, it鈥檚 harder for blood carrying oxygen and nutrients to get to the developing baby, said , an associate professor of pediatrics at the University of California-San Francisco School of Medicine.
鈥淚f anything is interrupting those functions 鈥 inflammation or clotting or differences in how the blood is flowing 鈥 that鈥檚 really going to affect how the placenta is working and being able to allow the fetus to grow and develop appropriately,鈥 she said.
It makes sense that we see the effects of covid in the placenta, Silverman said. 鈥淭he placenta is nothing more than a hyper-specialized collection of blood vessels, so it is like a magnetic target for the virus.鈥
Blood vessels in the placenta are smaller and may clot more easily than in the mother鈥檚 circulatory system, he said.
Permar said 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 . It鈥檚 an area in which she鈥檇 like to see more research.
There鈥檚 already that both mRNA-based and non-mRNA covid vaccines are safe for pregnant women.
Prahl co-authored a small, early and showed antibody protection persisted for both the mother and the baby after birth. 鈥淲hat we learned very quickly is that pregnant individuals want answers and many of them want to be involved in research,鈥 she said. Later studies, including one published in the journal Nature Medicine showing that getting a booster in pregnancy in the first four months of life, backed up her team鈥檚 findings.
Prahl expects more evidence will be available soon to support the benefits of mothers receiving a covid booster during pregnancy.
鈥淚 can say, kind of behind the scenes, I鈥檓 seeing a lot of this preliminary data,鈥 she said.
She blames the delay in part on the Biden administration鈥檚 scaling back of federal efforts to track covid. 鈥淎 lot of the surveillance of these data were pulled back,鈥 she said. The Trump administration is used to track covid.
But because the vaccines give a pregnant woman鈥檚 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.
鈥淚t will protect the pregnant person from more severe disease,鈥 she said.
Getting a covid vaccine while pregnant also helps protect newborns after birth. Pregnant women who get vaccinated pass that protection to their young babies, who can鈥檛 get their own shots until they are at least 6 months old.
released by the CDC in 2024, nearly 90% of babies who had to be hospitalized with covid had mothers who didn鈥檛 get the vaccine while they were pregnant.
As recently as April 2024, research showed that babies too young to be vaccinated had the highest covid hospitalization rate of any age group except people 75 and older.
The Trump administration鈥檚 decision to remove the covid vaccine from the list of shots it recommends for pregnant women means insurance companies might no longer cover it. Pregnant women who want to get it anyway may have to pay hundreds of dollars out-of-pocket.
鈥淚 don鈥檛 want to be that doctor who just says, 鈥榃ell, it鈥檚 really important. You have to vaccinate yourself and your kids no matter what, even if you have to pay for it out-of-pocket,鈥 because everyone has their own priorities and budgetary concerns, especially in the current economic climate,鈥 Silverman said. 鈥淚 can鈥檛 tell a family that the vaccine is more important than feeding their kids.鈥
But he and his colleagues will keep advising pregnant women to try to get the shots anyway.
鈥淣ewborns will be completely naive to covid exposure,鈥 he said. 鈥淰accinating pregnant women to protect their newborns is still a valid reason to continue this effort.鈥