COVID-19, New Moms and Breast Milk

As researchers expanded investigations into how the SARS-CoV-2 virus spreads, infects and who is most vulnerable, scientists at UC San Diego School of Medicine, in part supported by the Family Larsson-Rosenquist Foundation, focused on a particular aspect: breastfeeding women and breast milk.

In particular, they launched studies to determine whether COVID-19 is transmitted via human milk and whether human milk can protect infants from COVID-19.

To the first question, the answer appears to be no. A study published August 19, 2020 in JAMA analyzed 64 samples of breast milk collected by the Mommy’s Milk Human Milk Research Biorepository from 18 women across the United States infected with SARS-CoV-2. Although one sample tested positive for viral RNA, subsequent tests found that the virus was unable to replicate, and thus unable to cause infection in breastfed infants.

“Detection of viral RNA does not equate to infection. It has to grow and multiply in order to be infectious, and we did not find that in any of our samples,” said Christina Chambers, PhD, MPH, co-principal investigator of the study, professor of pediatrics at UC San Diego School of Medicine, director of Mommy’s Milk Human Milk Research Biorepository and co-director of the UC San Diego Center for Better Beginnings. “Our findings suggest breast milk itself is not likely a source of infection for the infant.”

The answer to the second question will take longer. Research is on-going, with study volunteers in the United States and Canada being monitored while breastfeeding and following infection. Scientists will also track infant growth and development via the child’s pediatrician for at least one year following infection.

“We already know breast milk contains properties that help protect infants from diseases, such as diarrhea and pulmonary infections. We want to know whether breast milk components, with their antiviral properties, might actually protect infants from COVID-19,” said Lars Bode, PhD, director of UC San Diego’s Larsson-Rosenquist Foundation Mother-Milk–Infant Center of Research Excellence (MOMI CORE).