Center Researchers Find No Infectious SARS-CoV-2 in Breast Milk from 110 Lactating Individuals
While viral materials from SARS-CoV-2 (the virus that causes COVID-19) has sometimes been detected in the breast milk of lactating individuals infected with COVID-19, it’s been uncertain whether this could lead to COVID-19 infection in a breastfed infant due to the small size of prior studies. Our new study, which was published in the journal Pediatric Research, examined this very question with a larger sample of chest/breastfeeding parents.
What did we do? Our Mommy’s Milk research program recruited 110 lactating individuals across the United States between March and September 2020. This included individuals who had a SARS-CoV-2 infection confirmed by RT-PCR, those who had symptoms of COVID-19 but were not tested, those who had symptoms but tested negative for SARS-CoV-2 by RT-PCR, and those exposed to an infected person. We collected information by interviewing moms and collecting two chest/breast milk samples: one when their symptoms peaked and a second milk collection after they had recovered.
What did we find? While we found that RNA (a type of genetic material) from SARS-CoV-2 can be infrequently detected in chest/breast milk after recent infection, we found no evidence that chest/breast milk contains infectious virus. We also found no evidence that breast/chest milk from a COVID-19 infected parent represents a risk factor for transmission of infection to infants.
So what’s the take-away? Lead author Dr. Paul Krogstad, a pediatric infectious disease researcher at the David Geffen School of Medicine at UCLA, said it best: “Breastmilk is an invaluable source of nutrition to infants. In our study, we found no evidence that breastmilk from mothers infected with COVID-19 contained infectious genetic material and no clinical evidence was found to suggest the infants got infected, which suggests breastfeeding is not likely to be a hazard.”