Large Study Confirms: COVID Vaccination During Pregnancy Shields Newborns From Infection

COVID Vaccination in Pregnancy Offers Real Protection for Newborns, Major Study Reveals

A comprehensive new study has confirmed what many medical professionals have long suspected — when a pregnant woman receives a COVID-19 vaccine, her baby benefits too. Published in the journal Pediatrics, the research tracked more than 140,000 children born in Norway over a three-year period and found measurable immune protection passed from vaccinated mothers to their newborns.

Why This Research Matters

Infants under six months of age cannot receive COVID-19 vaccines, yet this age group faces some of the highest rates of COVID-related hospitalization compared to most other demographics. In fact, U.S. data from a September 2024 study found that hospitalization rates for babies under six months rival those seen in adults aged 65 to 74 — and roughly one in five of those hospitalized infants required intensive care.

This vulnerability is precisely why the American College of Obstetricians and Gynecologists (ACOG) has long recommended that pregnant women get vaccinated against COVID-19. Last week, ACOG reaffirmed that guidance, and the new Norwegian study provides strong additional evidence in support of it.

"There are a number of studies that show one of the benefits of COVID vaccination during pregnancy is the passage of antibodies to the newborn, and then that protects the newborn against COVID," said Dr. Kevin Ault, a professor of obstetrics and gynecology at Western Michigan University Homer Stryker M.D. School of Medicine.

What the Study Found

Researchers at the University of Oslo followed 146,031 children born between March 2020 and December 2023, reviewing their medical records for up to two years after birth. Approximately one in four of the mothers had received a COVID vaccine while pregnant.

The key findings were striking:

• Infants in their first two months of life whose mothers were vaccinated during pregnancy were about 50% less likely to be hospitalized for COVID compared to babies born to unvaccinated mothers.
• Between 3 and 5 months of age, vaccinated-mother babies still showed a 24% lower risk of a COVID-related hospital visit.
• Beyond 6 months, the protective effect faded, highlighting the time-limited but critical window of immunity transfer.
• Babies exposed to the vaccine before birth showed no increased risk of hospitalization for other types of infections, contradicting unsubstantiated claims that maternal vaccination could impair a child's broader immune function.

Addressing Claims of Immune Disruption

The study's findings are particularly relevant in the current political climate surrounding vaccine policy. Robert Malone — appointed by Health Secretary Robert F. Kennedy Jr. to chair the CDC's vaccine advisory committee, though a federal judge recently ruled that appointment legally invalid — has repeatedly claimed without scientific evidence that COVID vaccines cause "immune dysregulation," potentially making recipients more susceptible to other infections.

This study directly contradicts that claim. If immune disruption were a real consequence, researchers would have observed higher rates of general infections in babies born to vaccinated mothers. They did not.

"The findings of this paper refute the whole idea of that being a problem," said Dr. Thomas Nguyen, a pediatrician and associate professor at Ohio University's Heritage College of Osteopathic Medicine.

Dr. Helena Niemi Eide, the study's lead author from the University of Oslo, echoed that conclusion: "We found that COVID vaccination in pregnancy protected the infant against COVID and had no apparent effect on other infections."

A Note on the Data

One nuance researchers acknowledged was that babies born to vaccinated mothers were about 5% more likely to visit a primary care physician for an infection. However, further analysis suggested this reflects behavioral differences rather than any biological effect — mothers who choose vaccination during pregnancy also tend to be more proactive about seeking medical care for their children overall.

"If you're more likely to get vaccinated during pregnancy, you're probably more likely to take your newborn to the doctor to be checked out," Dr. Ault explained. "There's not really a biological mechanism to explain those findings otherwise."

In Norway, where healthcare visits carry no out-of-pocket cost, this type of health-seeking behavior difference is a well-recognized factor that can influence study outcomes. The research team adjusted their analysis accordingly.

Scale and Independence of the Research

Dr. Nguyen noted that the study's large scale makes it especially credible. European nations with single-payer healthcare systems can track patient data across large populations far more easily than the fragmented U.S. system allows, lending the findings additional statistical power.

Importantly, the study received no funding from pharmaceutical companies. It was supported by the University of Oslo and a Scandinavian government research agency, and forms part of a broader ongoing research collaboration examining COVID vaccination outcomes during pregnancy.

The Bottom Line

For expectant mothers weighing the decision to get vaccinated, this study adds to a growing body of evidence that the COVID vaccine is not only safe during pregnancy but actively beneficial — both for the mother and for her baby during the most vulnerable early months of life. The protection may be temporary, fading around the six-month mark, but during that critical window when infants cannot yet be vaccinated themselves, maternal immunity may make a life-saving difference.