PRE-PRINT: Reassuring news about the safety of breastfeeding amidst the COVID-19 pandemic.

To doubly reassure mothers who want to breastfeed in these worrying times of a global pandemic, a new follow-up paper (IN PRE-PRINT) by Krogstad P et al. confirms that there is no evidence of infectious SARS-CoV-2 in human breast milk.

A paper was originally published in August 2020 with the first results of the study – that found no evidence of the replication-competent (active) virus in breast milk.

Now, 13 months later, as the Covid-19 global pandemic continues to spread around the world, Krogstad and colleagues, including Professor Lars Bode (featured in our microbiome academy), have released another paper - currently in preprint, so awaiting to be peer-reviewed.

This study includes a larger cohort of 110 breastfeeding women.

The study:

Breast milk samples from 110 women were collected.

  • 65 of the women were confirmed with a SARS-CoV-2 diagnostic test.
  • 36 had symptoms but without tests.
  • 9 had symptoms but a negative SARS-CoV-2 diagnostic test.

The results:

In the study group of 110 women, SARS-CoV-2 RNA was detected in the milk from 6 of the 65 women (9.2%) with recent confirmed infection.

"Neither infectious virus nor subgenomic RNA (a marker of virus infectivity) were detected in any of the samples."

The conclusion:

The second paper confirms the same result as the first paper.

There is no evidence of infectious SARS CoV-2 in breast milk, even if the mother tests positive for the coronavirus.

“We found no evidence that infectious SARS-CoV-2 is present milk from recently infected women, even if SARS-CoV-2 PCR tests are positive, providing reassurance of the safety of breastfeeding.”

The research team for this paper includes Professor Lars Bode. Professor Lars Bode is one of the 7 scientists featured in our Breast Milk and the Infant Microbiome course.

Reminder: This paper is a preprint. Preprints have not been peer reviewed.


Science reference:

Krogstad P, Contreras D, Ng H, Tobin N, Chambers CD, Bertrand K, Bode L, Aldrovandi G. No Evidence of Infectious SARS-CoV-2 in Human Milk: Analysis of a Cohort of 110 Lactating Women. medRxiv [Preprint]. 2021 Apr 7:2021.04.05.21254897. doi: 10.1101/2021.04.05.21254897. PMID: 33851178; PMCID: PMC8043475.

Easy-to-understand artice explaining more about the research***

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