Studies show that pasteurization inactivates breast milk SARS-CoV-2

August 13, 2020

A new study confirmed what researchers had already suspected: heat inactivates human milk SARS-CoV-2.

The findings show that the SARS-CoV-2 virus can be effectively inactivated by pasteurization. Photo: Lifeblood Milk

A team of medical researchers has found that pasteurization in breast milk inactivates the virus responsible for COVID-19. This confirmed that the milk bank process was and remains safe throughout the pandemic.

Survey – announced this month Journal of Pediatrics and Child Health – A partnership between UNSW and the Australian Red Cross Lifeblood Milk multidisciplinary team.

There are 5 breast milk banks in Australia. As the COVID-19 pandemic evolves, these milk banks will continue to provide donated breast milk to preterm infants who do not have access to their mother’s breast milk. Donors are screened for illness and milk is tested and pasteurized to ensure that it is medically safe for fragile babies.

There is no evidence that the virus can be transmitted through breast milk, but there is always a theoretical risk. We have shown that PDHM remains safe, as we have confirmed in previous pandemics that the supply of pasteurized donor breast milk (PDHM) could be interrupted for safety reasons. “

Greg Walker, Lead Author and PhD candidate for the Bill Laurinson Professor Group at UNSW Medicine

In this study, the team worked at the Kirby Institute’s PC3 lab to ly infect a small amount of frozen and freshly expressed breast milk from a healthy Lifeblood Milk donor.

“Then, a milk sample infected with SARS-CoV-2 was heated to 63°C for 30 minutes to simulate the pasteurization process performed in a milk bank. No, it’s a virus,” says Walker.

“Our findings show that the SARS-CoV-2 virus can be effectively inactivated by pasteurization.”

The researchers say their experiment simulated the worst theoretical scenario.

“The amount of virus we use in the lab is much higher than that found in breast milk in women with COVID-19, so we are really confident in these findings,” Walker said.

Dr. Laura Klein, a research fellow and senior research author at Lifeblood Milk, explains that the purpose of this study was to provide the evidence behind what people were already expecting.

“Pasteurization is well known for inactivating many viruses, including the coronavirus that causes SARS and MERS,” she says.

“These findings are consistent with recent studies that reported that SARS-CoV-2 was inactivated by heat treatment in some situations.”

Kirby Institute researcher and co-author of the study, Associate Professor Stuart Tarville, said the study was new.

“We have been working in real time to grow and create tools against this new pathogen. This was an exponential learning curve for all involved. This work and continued at PC3 Labs Much of the other work that we are doing shows how we can be safe at the forefront of handling this virus in the real world.”

Cold storage does not inactivate the virus

The researchers also tested whether storing SARS-CoV-2 in breast milk at 4°C or -30°C inactivates the virus. Storage conditions.

“We found that cold storage did not significantly affect infectivity. Viral load Walker says.

“Freezing milk reduced the virus present slightly, but we were able to recover viable virus after 48 hours of storage.”

Researchers found that the fact that SARS-CoV-2 was stable in refrigerated or frozen breast milk could help guide guidelines on the safe milking and storage of breast milk from mothers infected with COVID-19. There is.

For example, one mother with COVID-19 has found it especially important to ensure that her milk expressed is not contaminated with SARS-CoV-2. However, it is also important to note that breastfeeding is still safe for mothers with COVID-19. There is no evidence to suggest that SARS-CoV-2 may be transmitted via breast milk. “

Dr. Laura Klein, Research Fellow, Senior Research Author, Lifeblood Milk

Donated breast milk is recommended by the World Health Organization when the mother’s own breast milk is not available to reduce the risk of health problems that premature babies may face. Since its launch in 2018, Lifeblood Milk has provided donor milk to more than 1500 premature infants in 11 NICUs in New South Wales, South Australia and Queensland.