Breast Milk and COVID-19

Project DescriptionIn less than 6 months, SARS-CoV-2, the virus that causes COVID-19, has spread across the globeindiscriminately infecting persons regardless of social status or age. Pregnant women and children are notspared but in contrast to other respiratory viruses, SARS-CoV-2 infection does not appear to be more severe inthese groups. Nevertheless, there is considerable concern about transmission from mother to infant particularlyvia breast feeding. Many viral infections such as HIV, CMV, and Ebola are transmitted through breast milk.SARS-CoV-2 enters human cells using the ACE 2 receptor which is present in breast tissue. This increasesconcern that the virus may be present in the breast milk of infected women. Although most children doremarkably well with infection, children <1 year of age have more severe illness with high rates ofhospitalization and admission to the intensive care unit. Therefore, defining the risks of SARS-CoV-2 breastmilk transmission is of critical importance. However, breast milk is not only a potential vector of transmissionbut can be a vehicle of protection by the transfer of protective antibodies and other immune factors. Bothhumoral and cellular immune responses in milk, including milk antibodies to respiratory viruses such asinfluenza, modulate infant disease. In fact, infants less than 6 months of age rely on maternal antibodies toprotect them against influenza and other respiratory viruses. Maternal flu immunization protects infants for atleast 6 months not only against influenza but other febrile illnesses. Whether breast milk contains antibodies toSARS-CoV-2 and whether it modulates the risk of infection to the infant is unknown. Answering thesequestions will require assays to detect the virus and its immune response in milk. We propose to fill thesecritical gaps by validating a quantitative RT-PCR assay for detecting SARS-CoV-2 in breast milk and thentesting over 100 milk samples from women infected with COVID-19. We will also test heat inactivationprotocols used by breast milk banks to verify that Holder pasteurization destroys SARS-CoV-2. At present,breast milk banks will not accept donations from women who have had COVID-19. As the infection spreadsthis exclusion will limit the availability to sick and vulnerable infants. Finally, we will develop an assay to detectantibodies to SARS-CoV-2 expressed in breast milk and compare those to the antibodies present in maternalblood. Information about maternal transfer of SARS-CoV-2 specific antibodies to the infant is a high priority toinform both breastfeeding practices and SARS-CoV-2 vaccination strategies.