While pregnant and lactating women were largely not included in COVID-19 vaccine trials, two studies yesterday in Science Translational Medicine look at how the mRNA COVID-19 vaccines affect the groups differently than nonpregnant women and at how the sex of the fetus may affect maternal immune response and vertical antibody transmission.As Cristian Ovies, ScM; Eleanor C.
Semmes, MD-PhD candidate; and Carolyn B. Coyne, PhD, summarize in a related commentary, "These studies demonstrate that pregnant and lactating women mount robust antibody responses to vaccination and infection."However, factors such as time of vaccine priming and boosting as well as fetal sex modulate maternal antibody responses and passive immunity conferred on the