* Abbreviations: Caco-2 — : human epithelial colorectal adenocarcinoma SARS-CoV-2 — : severe acute respiratory syndrome coronavirus 2 TCID50 — : tissue culture infectious dose 50 Vero E6 — : Cercopithecus aethiops –derived epithelial kidney The current coronavirus disease 2019 pandemic, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), raises unprecedented questions regarding virus transmission and risks for pregnant or breastfeeding women. We and others described that SARS-CoV-2 RNA is detectable in the breast milk of infected mothers.1–3 In two cases in which the mother continued breastfeeding, the newborns also tested positive for SARS-CoV-2.1,2 However, the origin of the infections of the newborns remained unclear and raised concerns of possible virus transmission via breast milk. The safety and feasibility of breastfeeding is of high importance because breast milk contains nutrients, hormones, and immunoprotective entities that are essential for the development, health, and protection of the neonate. So far, the World Health Organization recommends continued breastfeeding after maternal SARS-CoV-2 infection while taking measures to maintain strict hygiene.4 We here explored the inactivation of SARS-CoV-2 spiked into human milk … Address correspondence to Janis A. Muller or Stephanie Pfaender, Abteilung fur Molekulare und Medizinische Virologie, Ruhr-Universitat Bochum, Universitatsstrasse 150, 44801 Bochum, Germany. E-mail: janis.mueller{at}uni-ulm.de or stephanie.pfaender{at}ruhr-uni-bochum.de