By Courtney Meehan
Professor and Associate Dean for Research and Graduate Studies
At the start of the COVID-19 pandemic, hospitals, health care providers, and policymakers were understandably worried that the SARS-CoV-2 virus could be transmitted via mother’s milk to her infant. Viral transmission through milk can occur, including transmission of human immunodeficiency virus (HIV), cytomegalovirus (CMV) and human T-cell lymphotropic virus type 1 (HTLV-1). With little data available on SARS-CoV-2, policy recommendations on infant feeding and maternal-infant contact were shifting and, at times, contradictory. Breastmilk is frequently the sole source of nutrition for young infants and the lack of information and variation in recommendations was leading to concern and anxiety for mothers and families.
Working with my long-time collaborators Michelle (Shelley) and Mark McGuire (University of Idaho) and new collaborators, Melanie Martin (University of Washington) and Sylvia Ley (Tulane University), along with a much larger team, we investigated whether human milk represents a potential mode of transmission for SARS-CoV-2, immune responses to infection in breastfeeding and non-breastfeeding women and infants, and whether infant feeding is associated with transmission risk.
The first few months of the pandemic were a blur, as my colleagues and I were working around the clock to design the study and secure funding. The need and urgency for data was clear. At the beginning, we were hearing reports that mothers were being separated from their infants. It was critical to conduct this study to evaluate the potential benefits and/or risks of breastfeeding if the mother was COVID-19 positive and ensure that policy surrounding infant care and infant feeding was evidence-based.
Our team was awarded a National Science Foundation (NSF) Collaborative RAPID grant. These grants are designed to support research that addresses an urgent need. I also received a WSU Health Equity Research Center Fellowship and collaborated on another related project led by University of Idaho and University of Rochester.
Conducting research during a pandemic has been a learning experience for the team. While many of the research members have conducted human milk and breastfeeding studies around the world (e.g., the international INSPIRE study, that I co-directed), conducting a national study during a pandemic was a new experience with unique challenges. Information on the virus and disease was being updated daily. We learned how to be flexible and to adapt quickly.
The group is enrolling COVID-19 positive breastfeeding and non-breastfeeding mothers and their infants and healthy (COVID-19 negative) breastfeeding mothers and their infants in a two-month longitudinal national study. Mothers and infants donate biological samples and engage in surveys at multiple time points across the study period. The team developed no-contact delivery and collection methods for the collection of human milk, breast swabs, stool, and dried blood spot samples. Mothers participate from their homes. Regular phone/Zoom calls allow the team to conduct surveys with participating mothers and are helping us understand disease severity, family health, changes in infant feeding practices, how mothers are managing isolation/quarantine recommendations, and maternal stress.
Beatrice Caffe (MA student in Evolutionary Anthropology), who is working with participating moms, noted, “It’s been challenging to help moms at a distance. Many are not feeling well and are taking care of a young infant. However, moms have been motivated to participate, volunteering during incredibly difficult times. They are experiencing the impact of this novel virus in their homes and they want to help researchers find the answers.”
The team published a review paper, “SARS-CoV-2 and human milk: What is the evidence?” in May in the journal Maternal and Child Nutrition. Much has changed since then. The first paper from the study, “COVID-19 and human milk: SARS-CoV-2, antibodies, and neutralizing capacity,” from the larger collaboration and focused on COVID-19 positive mothers, will soon be published in mBio. Results from this paper indicate that milk produced by women with mild-to-moderate COVID-19 does not appear to transmit SARS-CoV-2; infant viral exposure via contact breast skin remains a possibility (additional research to determine whether the viral RNA found on the breast is viable virus is needed); and breastmilk likely provides specific immunologic benefits to infants.
We are excited for the opportunity to contribute to the growing—but still incomplete—understanding of the SARS-CoV-2 virus and COVID-19, and their impacts on maternal-infant health. We are also incredibly grateful to the study participants who have worked with us during their illness, so that we can contribute to the scientific conversation surrounding COVID-19 and evidence-based guidance for healthcare providers and families around the world.
Additional information on the study and the research team can be found at wsu.edu/covid-19-infant-feeding.