‘A study published in JAMA: Pediatrics provides evidence that pregnant women may be able to pass IgG antibodies against SARS-CoV-2 to their fetus. The study involved 1,417 women who recently gave birth. Among 83 mothers with detectable SARS-CoV-2 antibodies, 72 (86.7%) transferred IgG antibodies to their fetus—as detected in the newborns’ cord blood. IgM antibodies were not detected in any cord blood specimens, and antibodies were not detected in any infants born to mothers without detectable antibodies. The concentration of antibodies in the cord blood was significantly correlated with the concentration in the mother, but the antibodies were successfully transferred by mothers who exhibited symptomatic disease and asymptomatic infection. The study did not explicitly evaluate the ability to transfer antibodies developed as a result of vaccination; however, the researchers indicate that the results align with similar studies on transplacental transfer of vaccine-conferred antibodies for other diseases. Further research is necessary to determine the recommended timing for vaccination of pregnant women in order to achieve sufficient transplacental transfer of SARS-CoV-2 antibodies to the fetus.’ [John Hopkins Newsletter]
Assessment of maternal and neonatal cord blood SARS-CoV-2 antibodies and placental transfer ratios
‘Our findings demonstrate the potential for maternally derived antibodies to provide neonatal protection from SARS-CoV-2 infection and will help inform both neonatal management guidance and design of vaccine trials during pregnancy. Further studies are needed to determine if SARS-CoV-2 antibodies are protective against newborn infection; if so, at what concentration; and whether the transplacental kinetics of vaccine-elicited antibodies are similar to naturally acquired antibodies.’
Read here (Jama Pediatrics, Jan 29, 2021)
