Multiple studies published in 2021 confirmed that the COVID-19 vaccine produced antibodies (proteins that fight infection) in umbilical cord blood and breastmilk samples but did not pass the vaccine itself. In addition, there is no evidence of adverse effects from vaccination on parents, fetuses, newborns, or breastfed babies. “With the COVID vaccine, you produce the antibodies to the spike protein on the COVID virus, and therefore the antibodies are passed on to the baby, giving the baby some protection against COVID as well,” explains Marcos Mestre, MD, vice president and chief medical officer at Nicklaus Children’s Hospital in Miami, Florida.
Research on Vaccine Safety
Multiple studies have confirmed the safety of the COVID-19 vaccine and benefits for pregnant and lactating parents. In one, researchers from Brigham and Women’s Hospital, Harvard University, and Massachusetts General Hospital looked at reproductive-age people who could get pregnant and had received one of the two COVID-19 mRNA vaccines. They tested samples from the 131 participants, including those who were lactating, pregnant, and non-pregnant. The study, published in March 2021 in the American Journal of Obstetrics & Gynecology, found vaccine-generated antibodies in the umbilical cord blood and the breast milk samples of vaccinated people. However, signs of the vaccine itself were not present. The potential for passing on those antibodies may help put more parents at ease with getting the vaccine.
Antibodies in Breastmilk
In April 2021, research published in JAMA also found antibodies in parents’ breast milk. In addition, evidence of antibodies in breastmilk was found in another study that was published in November 2021. The latter study found breastmilk antibodies in those who acquired immunity through infection and those who received immunity through vaccination. In both groups, the presence of antibodies lasted three months after infection or vaccination.
Adverse Effects and Side Effects
Additionally, researchers have found that none of the parents or infants experienced any serious adverse effects from the vaccine during the study period. In the JAMA study, many parents reported local pain after the immunizations—a common side effect—and four infants had upper respiratory tract infection with fever.
No Vaccine in Breastmilk
Another study from researchers at the University of California San Francisco found that mRNA from the COVID-19 vaccine was not detected in breast milk. Due to the ongoing nature of the pandemic, the results of this study, like many others, were published before peer review so that researchers, the medical community, and the public can have access to the most current data. The results are significant because the antibodies detected help both the parent and the baby.
Antibodies vs. Vaccine
Just about everyone is now eligible to get vaccinated for COVID-19 as both the Pfizer and Moderna mRNA vaccines have been approved for adults and children ages 6 months and older. COVID-19 vaccines are also now widely available. They continue to be free and can be found at local pharmacies, doctor offices, and pop-up vaccination clinics. The good news is that the vaccine itself does not spread to babies through the placenta or in breastmilk. Several studies have shown that the fetus and newborn only receive the antibodies, which is an important distinction. With the latest findings, organizations like the American College of Obstetricians and Gynecologists (ACOG) and the Centers for Disease Control and Prevention (CDC) recommend the COVID-19 vaccines for pregnant and breastfeeding people.
Breastfeeding Benefits
Breast milk provides nutrients for a baby and antibodies that the parent has acquired, including those from COVID-19 vaccination. It has the right amount of hormones and fatty acids like DHA for a baby to develop and grow. It’s also easy for an infant to digest. Numerous organizations recommend breastfeeding a newborn, if possible. Lactating parents must understand that they do not have to stop breastfeeding because they receive a COVID-19 vaccine. Health organizations recommend vaccination for lactating people because the vaccine’s benefits far outweigh the risks. In addition, multiple studies have confirmed the beneficial antibodies passed through breastmilk following vaccination and the diminished possibility of a baby having an adverse reaction to the parent’s vaccine.
COVID-19 Risks in Recently Pregnant People
People who are pregnant or were recently pregnant are at increased risk of severe complications from COVID-19, including needing to be hospitalized, receive intensive care, or require ventilation to help them breathe. Pregnancy causes changes in the body that make you more susceptible to becoming seriously ill from respiratory viruses. That’s why it’s crucial for those who recently gave birth to protect themselves from COVID-19. The best way to prevent infection is to get vaccinated. And if it has been more than six months since your second dose, the CDC recommends that you receive a booster shot. “Knowing that there have been studies showing the importance and actual transmission of antibodies to infants via breast milk and placental transfer with other clinical conditions/vaccines—including COVID-19—should help to reassure a families’ decision to receive the vaccine,” says Krysten Johnson, RN, who specializes in labor and delivery. If you are concerned about COVID-19 vaccination, seek the advice of a healthcare provider so you can make an informed decision. 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. A growing body of research has found that COVID-19 vaccination is safe during pregnancy and lactation. In addition, it may offer benefits to breastfeeding infants, as COVID-19 antibodies pass through breastmilk after vaccination.
