Placenta may have mechanism that protects fetus from Covid; vaccines safe with rheumatic diseases

The following is a summary of some recent studies on Covid-19. They include research that warrants further study to corroborate the findings and that has yet to be certified by peer review.

Placenta may shed proteins to keep virus out

The placenta may have a way to protect itself and the fetus from infection with the coronavirus, a small study suggests.

Researchers studied 24 women who gave birth between July 2020 and April 2021. Eight had symptomatic Covid-19 in the second trimester, eight were sick from the virus in the third trimester, and eight were not infected during pregnancy. When Covid-19 occurred in pregnancy, particularly during the third trimester, placenta cells appeared to "shed" a surface protein called ACE2 that the virus uses to break into cells and infect them, leaving fewer gateways for entry. Women who had Covid-19 in the third trimester had high levels of an enzyme called ADAM17 that is known to help ACE2 release itself from the cell surface, the researchers reported in The American Journal of Pathology.