Will Getting the COVID Vaccine While Pregnant Give Immunity to Baby?

Pregnant woman receiving the covid-19 vaccine

Getty Images

Key Takeaways

  • A baby has been born in South Florida with COVID-19 antibodies after her mother got the vaccine in her third trimester of pregnancy.
  • The antibodies were present in samples taken from the newborn's umbilical cord blood.
  • Doctors hope the antibodies will help to protect the baby against SARS-CoV-2, the virus that causes COVID-19. 
  • More research is needed to determine how long the protection might last.

The first confirmed case of a baby born with COVID-19 antibodies was reported in February 2021, with the findings presented in a study and published in Pediatrics.

Research had already established that pregnant people who were previously infected with COVID-19 can transfer antibodies to their baby in the womb. But the case study shows that the COVID-19 vaccine also gives a baby protection from COVID-19 before it's born.

UPDATE September 2022

Since the birth of that baby in South Florida in February 2021, there have been more studies done on the presence of antibodies from COVID-19 vaccination in pregnant people. In February 2022, researchers from Massachusetts General Hospital found babies born to pregnant people who were vaccinated had more lasting antibodies compared with babies born to unvaccinated parents who were infected with COVID-19. The study looked at individuals vaccinated between 20 and 32 weeks pregnant. In a separate study a few months earlier, researchers at NYU Grossman School of Medicine looked at 36 newborns whose parents were vaccinated during pregnancy. They found that 100% of the babies had protective antibodies at birth.

About the Case Study

The South Florida woman, a frontline healthcare worker, received her first Moderna COVID-19 shot when she was 36 weeks pregnant, and three weeks later she gave birth to a healthy baby girl. COVID-19 antibodies were detected in samples taken from the newborn’s umbilical cord blood, both immediately after birth and before delivery of the placenta.

"To our knowledge, this was the first in the world that was reported of a baby being born with antibodies after a vaccination,” co-author Paul Gilbert, MD, told the West Palm Beach ABC affiliate. "We tested the baby’s cord to see if the antibodies in the mother passed to the baby, which is something we see happen with other vaccines given during pregnancy."

Doctors have found that the antibodies will give the baby some protection against SARS-CoV-2, the virus that causes COVID-19. 

"We have demonstrated that SARS-CoV-2 IgG antibodies are detectable in a newborn's cord blood sample after only a single dose of the Moderna COVID-19 vaccine," wrote Dr. Gilbert and his co-author Chad Rudnick, MD. "Thus, there is potential for protection and infection risk reduction from Sars-CoV-2 with maternal vaccination."

Carl Weiner, MD

The likelihood was high that the COVID-19 vaccine, already found to be safe in non-pregnant women, would be safe for pregnant and breastfeeding mothers and generate protective IgG antibodies that would cross the placenta.

— Carl Weiner, MD

Research now shows that COVID-19 vaccines are safe and effective during pregnancy and breastfeeding for both the baby and pregnant person. Additionally, pregnant people who get COVID-19 are at higher risk of severe infection and other complications. For these reasons, pregnant people are highly encouraged to get vaccinated against COVID-19.

It's still unclear exactly how much immunity protection newborns get and how long it will last. "Further studies have to determine how long this protection will last. They have to determine at what level of protection or how many antibodies a baby needs to have circulating in order to give them protection," says Dr. Rudnick.

Another preprint study of 131 women (84 pregnant, 31 breastfeeding, and 16 non-pregnant), who all received the Pfizer or Moderna vaccine, was carried out at Massachusetts General Hospital.

The researchers found that maternal vaccine-generated antibodies were detected in the umbilical cord blood of all 10 babies who were delivered during the study period. The immune responses were equally strong in the pregnant and lactating women as in the control group, and antibodies were detected in the placenta and breast milk of every sample taken.  

Protection for Baby

Many other vaccines have been shown to pass antibodies from mother to baby via the placenta. "Vaccines not containing active virus have for decades been safely administered during pregnancy to protect either the mother or newborn, or both (e.g., influenza and whooping cough)," says Carl P. Weiner, MD, MBA, FACOG, professor of obstetrics and gynecology and professor of molecular and integrative physiology at University of Kansas School of Medicine.

Dr. Weiner explains that the vaccine doesn't reach the fetus, but rather causes the pregnant person to produce protective immunoglobulin G (IgG) antibodies—the most common type—that cross the placenta and circulate in the newborn for several months after delivery. Some vaccines also stimulate the production of protective immunoglobulin A (IgA) antibodies that enter into breast milk and are transferred to the breastfeeding newborn, he adds.

"The likelihood was high that the COVID-19 vaccine, already found to be safe in non-pregnant women, would be safe for pregnant and breastfeeding mothers and generate protective IgG antibodies that would cross the placenta and IgA antibodies that would be excreted into the mother’s milk," Dr. Weiner says. Thankfully, research confirms this.

COVID-19 Vaccine During Pregnancy

Pregnant people were excluded from the initial trials of the first three COVID-19 vaccines that are currently available in the US: Pfizer/BioNTech, Moderna, and Johnson & Johnson.

But Pfizer announced that the first large-scale trial of its vaccine on pregnant women was underway and expected to finish by the beginning of 2023. Moderna has created a registry to track pregnant people who get its shot.

Thousands of pregnant people have had the COVID-19 vaccine already, and it is strongly recommended during pregnancy and breastfeeding by both the Centers for Disease Control and Prevention and the American College of Obstetricians and Gynecologists.

Our knowledge is always evolving and more and more data shows that these vaccines are safe and effective during pregnancy and lactation, Dr. Weiner says. He points to accumulating research finding that both the Pfizer/BioNTech and Moderna COVID-19 vaccines are effective for pregnant people and their unborn or breastfed babies.

One study, published in the American Journal of Obstetrics and Gynecology, found that the vaccine-induced antibody levels in pregnant and lactating women were equivalent to non-pregnant women, and that breastfeeding women passed protective antibodies to their newborns.

The information in this article is current as of the date listed, which means newer information may be available when you read this. For the most recent updates on COVID-19, visit our coronavirus news page.

What This Means For You

If you're pregnant during the pandemic, you probably have lots of questions about your and your baby's health. Your OB/GYN is there to help you address any concerns.

If you get the COVID-19 vaccine during pregnancy, it will likely give your baby crucial protection from the virus.

8 Sources
Verywell Family uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Kubiak JM, Murphy EA, Yee J, et al. Severe acute respiratory syndrome coronavirus 2 serology levels in pregnant women and their neonatesAm J Obstet Gynecol. 2021;225(1):73.e1-73.e7. doi:10.1016/j.ajog.2021.01.016

  2. Shook LL, Atyeo CG, Yonker LM, et al. Durability of anti-spike antibodies in infants after maternal covid-19 vaccination or natural infection. JAMA. 2022;327(11):1087. doi:10.1001/jama.2022.1206

  3. Trostle ME, Aguero-Rosenfeld ME, Roman AS, Lighter JL. High antibody levels in cord blood from pregnant women vaccinated against COVID-19. American Journal of Obstetrics & Gynecology MFM. 2021;3(6):100481. doi:10.1016/j.ajogmf.2021.100481

  4. Centers for Disease Control and Prevention. Vaccines while pregnant or nursing.

  5. Gray K, Bordt EA, Atyeo C. COVID-19 vaccine response in pregnant and lactating women: a cohort study. Obstet Gynecol. doi:10.1101/2021.03.07.21253094

  6. BioNTech. Pfizer and BioNTech commence global clinical trial to evaluate COVID-19 vaccine in pregnant women.

  7. American College of Obstetricians and Gynecologists. COVID-19 vaccines and pregnancy: a conversation guide.

By Claire Gillespie
Claire Gillespie is a freelance writer specializing in mental health. She’s written for The Washington Post, Vice, Health, Women’s Health, SELF, The Huffington Post, and many more. Claire is passionate about raising awareness for mental health issues and helping people experiencing them not feel so alone.