COVID-19 antibodies pass through breast milk

INDIANAPOLIS (WISH) — There’s some good news for couples who’ve just welcomed a little one into the world.

A new study shows coronavirus antibodies — whether developed from a previous infection or after vaccination–can pass from mother to baby through breastfeeding. 

“We know that these antibodies are small enough so they can pass through the placenta and the baby is able to receive those antibodies and benefit from those antibodies,” Dr. Cameual Wright, VP market chief medical officer at CareSource, told News 8. “We also know those antibodies can pass through the breast milk. So, that’s one of the many benefits of breastfeeding. Some of the immunity the mom has can be shared with the baby.”

This is essentially how all viral antibodies work, Wright says. When a woman either contracts a virus or receives a vaccine her body mounts an immune response by producing antibodies against the foreign agent. If pregnant, these antibodies can then be passed to the child either in utero or by nursing, thus preventing infection.   

Researchers at the University of Idaho analyzed 37 milk samples from 18 women diagnosed with COVID-19. They found 62% of the samples contained significant amounts of two coronavirus antibodies. 

“Milk produced by infected mothers is a beneficial source of anti-SARS-CoV-2 IgA and IgG and neutralizes SARS-CoV-2 activity,” study authors said in the paper. “These results support recommendations to continue breastfeeding during mild-to-moderate maternal COVID-19 illness.”

News 8’s medical reporter, Dr. Mary Elizabeth Gillis, D.Ed., is a classically trained medical physiologist and biobehavioral research scientist. She has been a health, medical and science reporter for over six years. Her work has been featured in national media outlets. You can follow her on Facebook @DrMaryGillis and Instagram @reportergillis.