The COVID-19 pandemic introduced many new considerations for health, and for breastfeeding parents, questions arose about the safety and implications of vaccination. Parents often seek to understand how the vaccine might affect their milk supply, their own health, and, most importantly, the well-being of their infant. Understanding scientific consensus and official guidance is important for informed decisions. This article provides information about COVID-19 vaccination for breastfeeding individuals, covering safety recommendations and the potential transfer of protective antibodies to infants.
Official Guidance and Safety for Breastfeeding Parents
Major health organizations, including the Centers for Disease Control and Prevention (CDC), the World Health Organization (WHO), and the American College of Obstetricians and Gynecologists (ACOG), recommend COVID-19 vaccination for breastfeeding individuals. These recommendations are based on safety data indicating no harm to the nursing parent or breastfed infant. The Academy of Breastfeeding Medicine also supports COVID-19 vaccination for all breastfeeding individuals.
Studies have shown that COVID-19 vaccines do not contain live virus particles, so they cannot cause infection in the vaccinated person or their baby. Scientific investigations have found no evidence that vaccine components, such as messenger RNA (mRNA) or synthetic lipids, pass into breast milk in amounts that would harm the infant. If any minute amounts were to enter breast milk, they would likely be quickly inactivated by the baby’s digestive system.
Safety monitoring of COVID-19 vaccines in breastfeeding individuals has revealed no severe reactions in the parent or infant after initial doses or booster shots. The understanding is that the benefits of vaccination, including protection against severe illness for the breastfeeding parent, outweigh any theoretical risks for the infant. Breastfeeding should not be interrupted or discontinued due to vaccination.
Transfer of Antibodies to Infants
After a breastfeeding parent receives a COVID-19 vaccine, their immune system produces antibodies that can transfer to the infant through breast milk. This process offers the infant passive immunity. While the infant does not develop their own active immune response from the vaccine, these transferred antibodies may provide a degree of protection.
Breast milk contains various types of antibodies, primarily secretory IgA (sIgA) and immunoglobulin G (IgG). IgA antibodies, which are highly abundant in breast milk, are particularly effective in protecting the infant’s mucous membranes by preventing pathogens from attaching. IgG antibodies, also found in breast milk, provide systemic immune protection.
Research has consistently detected SARS-CoV-2 specific IgA and IgG antibodies in the breast milk of vaccinated mothers. For instance, one study found strong production of IgA and IgG antibodies in breast milk for at least six weeks post-vaccination, with 97% of samples showing elevated levels. These antibodies have demonstrated neutralizing effects against the SARS-CoV-2 spike protein and several variants, indicating their potential to protect the infant from infection. The levels of these antibodies can increase after the second dose of the vaccine, with IgA peaking around two weeks and IgG around four weeks after vaccination.
Addressing Specific Concerns
Breastfeeding parents may have specific worries regarding COVID-19 vaccination, including potential impacts on milk supply. Studies indicate that while some individuals report temporary changes in milk supply, these instances are generally not significant or long-lasting, typically returning to normal within a day or two.
Concerns about infant adverse reactions after maternal vaccination are common. Current data show that severe adverse effects in breastfed infants are extremely rare. A small percentage of infants might experience mild, temporary symptoms, but these are generally self-limiting. It is not definitively known if these mild reactions are directly caused by the vaccine.
Health authorities and scientific studies agree that the benefits of COVID-19 vaccination for the breastfeeding parent outweigh any theoretical risks. Vaccination protects the parent from severe COVID-19 illness and hospitalization, which in turn safeguards the infant by keeping the caregiver healthy.