In the first nine months of the pandemic, an estimated 116 million babies were born worldwide, according to Unicef estimates. This prompted researchers to scramble to answer a critical question: can the virus be transmitted through breast milk? Some people have assumed it can. But because several groups of researchers tested the milk, they found no traces of viruses, only antibodies, suggesting that drinking the milk could protect babies from infections.
The next big question for breast milk researchers was whether the protective benefits of a Covid vaccine could just as easily be passed on to babies. None of the vaccination trials included pregnant or breastfeeding women, so researchers had to find lactating women who qualified for the first vaccination.
Through a Facebook group, Rebecca Powell, a human milk immunologist at the Icahn School of Medicine on Mount Sinai in Manhattan, found that hundreds of doctors and nurses are willing to share their breast milk regularly. In her most recent study, which was not formally published, she analyzed the milk of six women who received the Pfizer BioNTech vaccine, and four who received the Moderna vaccine, 14 days after the women received their second shots. has. She found significant numbers of one specific antibody, called IgG, in all of them. Other researchers have had similar results.
“There’s reason to be excited,” he said. Dr. Kathryn Gray, a fetal medicine specialist at Brigham and Women’s Hospital in Boston, who conducted similar studies. “We assume it can provide some protection.”
But how do we know for sure? One way to test this – to expose babies to the virus – is, of course, unethical. Instead, some researchers tried to answer the question by studying the properties of the antibodies. Neutralize it, which means that it prevents the virus from infecting human cells?
In a draft of a small study, one Israeli researcher found that this was so. “Breast milk can prevent the spread of viruses and the ability of the virus to infect host cells that cause disease,” Yariv Wine, an applied immunologist at Tel Aviv University, wrote in an email. .
Research is too early for vaccinated mothers who are breastfeeding to act as if their babies could not be infected, said Dr. Kirsi Jarvinen-Seppo, head of pediatric allergy and immunology at the University of Rochester, said. Dr. Jarvinen-Seppo conducted similar studies. “There is no direct evidence that the Covid antibodies in breast milk protect the baby, only evidence to suggest that this may be the case,” she said.