American Journal of Obstetrics and Gynecology Paper Says COVID Vaccine Crosses Placenta Barrier

This is a pre-print. It has not been peer-reviewed as of yet.

American Journal of Obstetrics and Gynecology:

SARS-CoV-2 infection presents substantial challenges to global health, necessitating effective 45 interventions such as COVID-19 vaccination. The initial clinical trials for the COVID-19 mRNA 46 vaccines excluded pregnant women, leading to a knowledge gap concerning the potential 47 biodistribution of the vaccine's mRNA to the placenta and or the fetus after maternal vaccination. 

The Pfizer and Moderna Assessment Reports provided to the European Medicines Agency1,2 48 49 concluded that in animal models, a fraction of the administered mRNA dose is distributed to distant 50 tissues, mainly the liver, adrenal glands, spleen, and ovaries. 

Another animal study showed that 51 lipid nanoparticles (LNPs)-mRNA injections, similar in composition to COVID-19 mRNA vaccines, delivered functional mRNA to the placenta and other fetal organs. 52 3 

Our recently published study 53 demonstrated that the COVID-19 vaccine mRNA administered to lactating mothers can spread systemically from the injection site to breast milk, indicating it could cross the blood-milk barrier.4,5 54 55 

Another study evaluating the effects of maternal COVID-19 vaccination on the hematopoietic stem 56 progenitor cells in the umbilical cord blood suggested that the LNPs/mRNA vaccines might reach the fetus following maternal vaccination. 6 57 This report presents two unique cases wherein pregnant 58 individuals were vaccinated with the COVID-19 mRNA vaccine shortly before delivery. 

This study 59 aimed to assess the presence of COVID-19 vaccine mRNA in the placenta and cord blood 60 following maternal vaccination during human pregnancy.