COVID-19, Pregnancy, and Protection
Determining what keeps fetuses of SARS-CoV-2-infected mothers safe from the ill effects of COVID-19
By Jeffrey Laurence, M.D
As COVID-19 swept into the U.S. in early 2020, several amfAR-funded scientists utilized their expertise and technology, honed in studying HIV, to address this new viral threat.
amfAR also launched a new grant program to explore specific aspects of SARS-CoV-2, the viral cause of COVID-19. One issue involved pregnant women, who were at increased risk of severe disease and death following SARS-CoV-2 infection. This was thought to be due to immune adaptations characteristic of pregnancy, which block rejection of a foreign tissue: the fetus. Remarkably, when appropriate precautions were undertaken in SARS-CoV-2-infected mothers who breastfed, only 3% of their newborns became infected. The mechanisms behind such a beneficial result remained unclear.
Dr. Andrew Badley, an amfAR-funded researcher at the Mayo Clinic, and colleagues in the U.S. and India found a strong correlation between levels of anti-SARS-CoV-2 antibodies in the blood of the pregnant women and in their newborns, and the ability of those antibodies to inactivate the virus. Antibody levels were highest if the women had been infected during the third trimester of pregnancy. Despite the marked pro-inflammatory response occurring in infected mothers, infants appear to have been protected from injury by the simultaneous appearance of anti-inflammatory proteins as detected in their umbilical cords.
The authors emphasize three important conclusions. First, potentially protective antibody responses against the COVID-19 virus can be transferred to the fetus. Second, vaccination of the pregnant women generates the highest levels of these antibodies, particularly when the vaccine is administered in the third trimester. Finally, fetal cord blood of infected mothers contains anti-inflammatory proteins that may counteract the adverse effects of COVID-19 infection for the fetus.
amfAR was a funder of this research.
Dr. Laurence is amfAR’s senior scientific consultant.