Breastmilk Could Protect Babies – And Adults – From Covid. Here's How

Breastmilk from mums who've caught the virus retains key antibodies 10 months after infection.

Mothers who’ve been infected with Covid-19 continue to pass antibodies via their breastmilk for 10 months, new research suggests.

The study, led by immunologist Dr Rebecca Powell, suggests breastmilk can offer infants protection from the virus for almost a year. The researchers also believe breastmilk could be used in the treatment of Covid-19 patients, potentially cutting the number of adults needing intensive care.

Dr Powell’s team analysed breast milk samples from 75 women who had recovered from Covid-19 and found that 88% contained a type of antibody called Immunoglobulin A, or IgA.

IgA works to protect body surfaces – such as the respiratory tract and gut – that come into contact with outside organisms. The researchers found that most IgA antibodies present in breastmilk could neutralise Sars-CoV-2, the virus that causes coronavirus.

FatCamera via Getty Images

The researchers also looked at the transfer of antibodies in 50 breastfeeding women who’d received a coronavirus vaccination. They found that women who’d received the Moderna vaccine passed on the most antibodies via breastmilk, closely followed by the Pfizer vaccine.

Women who’d had the Johnson & Johnson vaccine – which is used in the US – had the lowest number of antibodies detected in their breastmilk of the three vaccines tested. The researchers are currently investigating antibodies in breastmilk following the AstraZeneca vaccine.

Dr Powell, when presenting the research at the Global Breastfeeding and Lactation Symposium, said that as well as protecting babies, human breastmilk could be used in hospital treatments for other patients.

“It could be an incredible therapy, because Secretory IgA is meant to be in these mucosal areas, such as the lining of the respiratory tract, and it survives and functions very well there,” she said, according to the Guardian.

“You could imagine if it was used in a nebuliser-type treatment, it might be very effective during that window where the person has gotten quite sick, but they’re not yet at the point of [being admitted to intensive care].”

Previous research has also detected Covid antibodies in the breastmilk of mothers, but until now, it’s been unclear how long this protection may last.

In August, research from the University of Florida concluded breastmilk can contain “a significant supply of antibodies” offering infants “passive immunity”. The levels of antibodies noted were higher after vaccination, compared to natural infection. The researchers said this is yet another reason why pregnant women should get the coronavirus vaccine.

“Think of breast milk as a toolbox full of all the different tools that help prepare the infant for life. Vaccination adds another tool to the toolbox, one that has the potential to be especially good at preventing Covid-19 illness,” associate professor Joseph Larkin III said.

“The results of our study strongly suggest that vaccines can help protect both mum and baby, another compelling reason for pregnant or lactating women to get vaccinated.”