Further evidence that mRNA vaccination against SARS-CoV-2 is safe during pregnancy

BRIGHAM AND WOMEN’S HOSPITAL

Many public health initiatives today are focused on protecting vulnerable populations against the novel coronavirus and recommend that pregnant women routinely receive mRNA vaccines to prevent maternal and fetal morbidity as well as mortality. To gather more data on vaccine safety and any effects on the fetus, researchers at the Brigham sought to understand if any Spike protein from the virus can accumulate or undergo translation in the placenta post-vaccination. The group identified 48 patients receiving one or two doses of an mRNA SARS-CoV-2 vaccine during gestation and subsequently quantified the expression of the Spike protein in preserved placental tissue. In doing so, they discovered that all placentas in the study and their corresponding negative control groups did not express the Spike protein. Moreover, the six placentas with the shortest vaccination-to-delivery intervals were tested for SARS-CoV-2 Spike RNA and were negative. Both observations provide further evidence that mRNA vaccines are safe for the growing fetus.

“Our findings were derived from pregnant patients in real-life conditions and underscore the portended safety of mRNA vaccination during pregnancy,” said senior author Carlos Parra-Herran, MD, from the Department of Pathology. “We are now eager to continue understanding the safety of mRNA vaccines during pregnancy in order to expand vaccination efforts and better protect our vulnerable populations,” added lead author Andres Santos MD, PhD, also from the Department of Pathology.