Is the COVID vaccine safe while breastfeeding?

What does the evidence say about COVID vaccine while breastfeeding?

1. No evidence suggests that receiving a vaccine against SARS-CoV-2 is harmful to either the nursing mother or the breastfed infant. Antibodies and T-cells that neutralize the virus appear in milk after maternal vaccination, and milk antibody levels persist for at least 6 to 8 months. 1
2. Only a small percentage of milk samples from women who received an mRNA vaccine contain trace amounts of mRNA, and mRNA has not been detected in the serum of any breastfed infant. A small percentage of breastfed infants may have sleepiness, increased fussiness, fever, rash or self-limiting diarrhea, with no serious adverse effects reported. 1
3. A 2022 systematic review found mRNA present in some milk samples at a maximum of 2 ng/mL without damage to the newborn, described a biphasic IgA response peaking about a week after a dose and IgG detectable four weeks and even six months later, and reported decreased milk supply under 24 hours in 7 percent of lactating women. 2
4. A 2025 study of adverse reactions found severe reactions were rare, with one documented case of loss of breast milk among 213 breastfeeding participants (0.1 percent). The most common reactions were injection site pain (26.2 percent), dizziness or fatigue (12.1 percent) and fever below 39 degrees Celsius (15.8 percent). 3
5. The virus itself has not been found to pass into breast milk, and nursing parents with COVID-19 are advised to wash their hands frequently and wear a mask while nursing. Staying up to date with recommended COVID-19 vaccines is described as the best way to protect yourself and others. 4

How COVID vaccine changes by nursing stage

• Early weeks. The newborn weeks, when supply is still settling and any change feels alarming. Temporary supply dips have been reported, and in all cases the milk supply returned to normal within 3 days. A small number of parents have also reported a blue or blue-green discoloration of their milk.
• Established nursing. Established feeding. This is where the antibody story matters most: milk antibody levels persist for at least 6 to 8 months after vaccination, so the protective transfer is not a one-week event.
• Weaning. Older baby and less frequent feeds. Only a small percentage of milk samples from parents who received an mRNA vaccine contain trace amounts of mRNA, and mRNA has not been detected in the serum of any breastfed infant.