Breastfeeding offers numerous immunological, developmental, and psychological advantages to the infant–mother dyad. The risks posed to infant and maternal health through any loss of support for breastfeeding mean that public health messaging during the COVID-19 pandemic should be careful. As academic leads of human milk banks, we are acutely aware of the importance of understanding the risks posed by novel infectious pathogens in human milk and the mitigation of risk to susceptible infants.
It is therefore essential that published data related to COVID-19 are valid beyond question. In their Correspondence, Rüdiger Groß and colleagues1 describe the detection of viral particles in human breastmilk, but no cell culture to measure viral viability was done. Furthermore, the likelihood of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) being introduced into milk samples from the infant saliva via retrograde milk flow was not considered.2, 3 Personal communication with Groß and colleagues confirmed that the infant was fed just before sample collections. SARS-CoV-2 is present in saliva during the first week of signs,4, 5 and the baby showed signs of infection that coincided precisely with the period in which positive milk samplings were collected.
The haste to publish has created possible false narratives associated with major harm (two of the four cited articles in the aforementioned Correspondence1 were non-peer-reviewed preprints). Since the Correspondence by Groß and colleagues1 was published, results of larger studies have shown no viable infectious virus in breastmilk and that breastfeeding is probably not a mode of SARS-CoV-2 transmission.6 Mothers should be supported to establish and continue breastfeeding if they are positive for COVID-19.7 Epidemiological evidence suggests the harms of breastfeeding cessation disproportionately outweigh the risk of COVID-19 transmission.
Acknowledgments
NSS declares funding from UK Research and Innovation as a Future Leaders Fellow at Imperial College London; and is a cofounder and non-remunerated trustee of the Human Milk Foundation. All other authors declare no competing interests.
References
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