Holder Pasteurization Inactivates SARS-CoV-2 in Human Breast Milk

Background: SARS-CoV-2, the etiological agent causing the COVID-19 pandemic, has quickly developed to be a major public health issue. Recently, SARS-CoV-2 RNA has been detected in human breast milk samples of infected mothers, raising concerns regarding the safety of breastfeeding upon infection. We here explored the possibility of viral inactivation in human milk samples by holder pasteurization. Methods: We spiked individual breast milk samples with five SARS-CoV-2 isolates, heated them to 63°C for 30 minutes, and determined the residual infectivity by TCID 50 titration. Findings: Infectious SARS-CoV-2 in breast milk is inactivated by holder pasteurization. Interpretation Holder pasteurization provides an alternative and safe option for infected mothers to continue feeding breast milk to their infants during active SARS-CoV-2 infection. Funding: Horizon 2020, the German Research Foundation, the Baden-Wurttemberg Stiftung. Declaration of Interests: The authors declare no competing interests. Ethics Approval Statement: Ethical approval by the ethics commission of Hanover Medical School, Hanover, Germany and the ethics committee of Ulm University. All mothers provided written informed consent for the collection of samples and subsequent analysis.