Antibodies to the SARS-CoV-2 coronavirus in the blood of pregnant women cross the placenta efficiently and are found at similar concentrations in the blood of their newborns, according to a new study.

The findings suggest that mothers who have had COVID-19, or asymptomatic exposure to the coronavirus, can provide some protection against the virus to their newborns through this antibody transfer.

The authors of the new paper in JAMA Pediatrics hypothesize this may have implications for COVID-19 vaccines.

Researchers tested blood samples from 1,471 women and their newborns for the presence of antibodies to SARS-CoV-2, and found that 83 of the women had significant levels of SARS-CoV-2-specific antibodies.

The vast majority (87%) of the newborn babies of these women also had significant levels of SARS-CoV-2-specific antibodies in samples of umbilical cord blood drawn at birth. The study found no evidence that fetal infection caused the antibodies, indicating that it is likely the antibodies crossed the placenta from the mother’s blood to the fetal circulation.

“This transfer appears to be pretty efficient,” says study co-senior author Karen Puopolo, a neonatologist at Children’s Hospital of Philadelphia, an associate professor of pediatrics at the University of Pennsylvania Perelman School of Medicine and chief of the Section on Newborn Medicine at Pennsylvania Hospital. “In some of the cases, the newborn’s blood concentration of SARS-CoV-2 antibodies was even higher than the mother’s.”

“In general, our findings are consistent with what we know about cross-placental transfer of antibodies to other viruses, and should contribute to the discussion about whether and when to vaccinate pregnant women against SARS-CoV-2,” says co-senior author Scott Hensley, an associate professor of microbiology at Penn Medicine and a member of the Penn Institute for Immunology.

Read the full article about transferring COVID-19 antibodies to newborns by Melissa Moody at Futurity.