Breastmilk: A Source of SARS-CoV-2 Specific IgA Antibodies

Since the outbreak of coronavirus disease 2019 (COVID-19), many put their hopes in the rapid development of effective immunizations. As this intervention will not be available on a short notice, patient isolation, physical distancing, protective materials and good hygiene are currently the sole measures for prevention. Here we provide multiple lines of evidence on the presence of a variety of antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) present in breastmilk from mothers who have recovered from COVID-19, with no such antibodies present in the controls. These antibodies are capable of neutralizing a clinical isolate of SARS-CoV-2 in vitro . We furthermore show that high pressure pasteurization hardly affects antibody levels and efficacy. We hypothesize that breastmilk, obtained from mothers who have recovered from COVID-19, may serve as a safe and widely applicable preventive strategy.Trial Registration: This research project was registered at the Dutch Trial Register on May 1st, 2020, number: NL 8575Funding Statement: The study was funded by de Stichting Steun Emma Kinderziekenhuis. No payment by a pharmaceutical company or other agency was made.Declaration of Interests: The authors have no conflicts of interest to declare.Ethics Approval Statement: Ethical approval was obtained from the Medical Ethics Committee of Amsterdam UMC, location VUmc and written informed consent was obtained from all participants.