Now, researchers from Weill Cornell Medicine have found that pregnant women can pass antibodies to their babies in the womb. The researchers speculate that pregnant women who are vaccinated are also likely to share their positive immune response with their newborns.
“Since we can now say that the antibodies pregnant women make against COVID-19 have been shown to be passed down to their babies, we suspect that there’s a good chance they could pass down the antibodies the body makes after being vaccinated as well,” said researcher Dr. Yawei Jenny Yang.
Passing down antibodies
The researchers had nearly 90 pregnant women with COVID-19 antibodies involved in the study, and they all gave birth at New York Presbyterian Medical Center between March and May of 2020. After giving birth, the researchers tested the babies’ umbilical cord blood to see if the mothers’ antibodies were shared in the womb.
Nearly 80 percent of the newborns were born with COVID-19 antibodies in their umbilical cord blood. This was true despite the fact that nearly 60 percent of the women involved in the study never had COVID-19 symptoms, even though they were exposed to the virus. However, having an asymptomatic case affected both the mothers’ and babies’ antibody count; women who were asymptomatic had lower antibody totals, and so did their babies. The opposite was also true -- symptomatic cases led to more antibodies for women and babies.
It’s important to note that all of the infants tested negative for COVID-19 at birth. This is encouraging because the newborns were still able to receive the benefits of the antibodies without experiencing the virus firsthand.
How will vaccinations play a role?
Now knowing that women can pass their antibodies through the placenta to their newborns during pregnancy, the researchers are interested in seeing how vaccinating pregnant women will affect their babies in the womb.
“The $1 million question is: Will the group of women who are now being vaccinated get the same type of protection?” said researcher Dr. Laura Riley. “We don’t know that yet. Getting those answers is going to be really important.”